GENERAL TWIN SEAL™ Operation, Maintenance & Service Manual
Contents
1. a 6921 16 C821 BUSHING 4 1 10 cat 16 921 SLIP 4 921 10 caz1 18 C411 PLUG 4 con 10 18 Catt BODY cat 1 20 C411 O RING 6 caet 10 cet 20 0421 GASKET 6 821 10 coat 20 LOWER PLATE 6 841 12 0411 24 0411 BUSHING 6 cen i2 421 24 C421 sTuD HEX NUT This most popular General Twin Seal design employs PIPE PLUG bushings and requires a single gland BUSHINGS TWO GLANDS 72 CAP SCREW 6 GLAND 62B O RING 71 STUD 75 N 62A O RING 820 BACKUP RING 76 PIPE PLUG 63 PACKING 46 BUSHING 2 BONNET 49 GASKET 1 ee ona 62E BACKUP RING 4 PLUG 5 suP BUSHING 49 GASKET 76 PIPE PLUG 71 STUD 75 NUT 72 CAP SCREW 62c o RING 62E BACKUP RING 63 PACKING 628 O RING 3 LOWER PLATE 62A O RING L 62D BACKUP RING 6 GLAND Typical Arrangement of C851 3 C861 a C851 e C851 Higher pressure class valves employ the balanced plug design to minimize plug hydro forces which in tum requires two glands GENERAL VALVE COMPANY BEA2. Laing aripa wah ona gaar fh nce l 26514 25514 Bearing Gap I dear ofthe housing 14 Remove the socket head screw 38 and push the indicator shaft sub 9 27 406 27 406 indicator Flag 1 assembly 10 out trough the batom on the wer stem 4 10 27 488 27 488 Indicator Shaft 1 16 Remove the lower stem 4 from the upper stem 3 11 28 402 28 402 Handwheel 1 16 Remove the bearings 26 from the upper stem 3 12 41 402 41 402 Drive Pin 1 13 41 496 41 496 Guide Pin 1 OPERATOR ASSEMBLY 14 41 411 41 411 Coupling Pin 1 1 Install the two bearings 26 at top of upper stem 3 NOTE These are radial 15 42 403 42 403 Nut thrust bearings and must be installed such that the widest surfaces of the inner raceways are back to back INCORRECT INSTALLATION WILL 38 BE Ez Washer RESULT IN SERIOUS DAMAGE Yr 545402798 Key 1 2 install the bearing retaining ring 40 18 45 404 45 404 Key 1 3 Apply a coating of grease to all surfaces of the upper stem 3 19 48 412 48 412 Roller 1 4 Thread the upper stem 8 the lower stem 4 such that the drive pin 20 6213 6213 O Ring 1 inthe upper stem comes against the shoulder at the TOP of lover stem 21 62208 62208 O Ring 1 and the detent recess in the upper stem is exactly in ine with the roler opening in 22 64 411 64411 Protector 1 This operation may requie several attempts as the threads
3. 23 66 483 66 476 Ball Bearing 2 24 86 481 66 477 Cup Bearing 2 25 66 482 66 478 Cone Bearing 2 26 69 414 69 414 Spinner Handle 1 27 725 725 Cap Screw 8 28 72 18 7210 Cap Screw 1 29 7221 7226 Cap Screw 1 30 76 891 76 594 Plug T 31 76612 76 612 Lube Fitting 1 32 T7422 77 47 Coupling Pin 2 33 77 480 77 418 Dowel Pin 1 34 77451 77 440 Indicator Pin 1 35 98 790 98 663 Stop Screw 1 OPERATOR ASSEMBLY 1 Install O Ring 21 in the stem bushing 14 in the Operator Housing 1 Place beating 23 in the top of the operator housing 1 2 Apply a liberal coating of grease to all surfaces of the operator stem 3 and the upper stem 4 Thread the operator stem into the upper stam such that the dowel pin 5 comes against the shoulder at the BOTTOM of the upper stem and the detent recess in the operator stem is exactly in ine with the roller opening at the bottom of the upper stem This operation may require several attempts as the threads are multiple start and do not always assemble correctly with the first try 3 Place the roller 16 inthe opening of the upper stem 4 and the detent recess of the operator stem 3 An application of grease wil hold itin position 4 Postion the operator housing such that when viewed from above the raised portion of the cam is in the lower left quadrant of the housing bore see cross section illustration With ro
4. 38 24401 Washer 18 45402 20 45428 Key 21 48409 Roller 22 6220 O Ring 23 62215 O Ring 24 8412 Protector 25 6416 Plastic Plug 26 65401 Grease Seal 27 66 404 Ball Bearing 28 65452 Bal Bearing 29 66 454 Bearing Cone 30 66463 Bearing Cup 31 69 414 Spinner Handle 32 7147 Sud 33 725 Cap Sorew 34 728 Cap Screw 35 7226 CapScrew 38 7254 Cap Screw 37 73411 Screw 38 73 131_ Cap Screw 39 748 Screw 40 75406 Nut 41 76412 Lube Fiting 42 76536 PipePlug 43 77454 Dowel Pin 44 7781 Rolpin 45 18407 Retaining Ring 1 1 8 no Js gt co fn 3 rof 8141 1 1 1 1 1 1 1 1 1 141 1 1 1 1 1 141 1 1 1414141 1 1 13 not available separately GENERAL VALVE COMPANY TWIN SEAL MODEL 1500 G Cross Section Exploded View SHIELDS NOT SHOWN 2589424 2585482 1500 G Is Used on Models 20 C841 is C941 Handwheel not shown 30 821 36 11 TWIN SEAL MODEL 1500 OPERATOR DISASSEMBLY 20 Instali ball bearing 27 over upper stem and secure with upper st
5. Tighten cap screws 27 in gear housing cover 7 1 Assemble handwheel 9 key 12 washer 11 and cap screw 29 on the worm shaft 12 Place a drift punch through the hole in the top of the operator stem to prevent itfrom tuming With the punch at 90 10 the worm shaft the handwheel Clockwise and run the upper stem down as far as it wil go Place the coupling 10 onthe bottom of the operator stem with the horizontal portion of the L shaped groove at the bottom Tum the coupling until the coupling pin hole in the operator stem is aligned with the top hole in the coupling and the vertical groove without the ramp is aligned with the stop screw boss in the housing Drive the coupling 32 nto the hole in the top of the coupling and the bottom hole of the operator stem Install the stop screw 35 and the dowel pin 83 NOTE The coupling 10 has an L shaped groove on both sides The Vertical portion of one ofthe grooves has a ramp atthe top The coupling must be installed such that the side without the ramp is adjacent to and engages the stop screw The ramp is used to actuate the automatic body bleed valve when installed 18 Install O Ring 21 in the top of the gear housing and O Ring 18 in the top ofthe lower stem 3 Place the indicator stem 8 on the top of the operator stem and down through the gear housing Install the indicator pin 34 GENERAL VALVE COMPANY not available separately TWIN SEAL MODEL 6
6. 1 3 A E 3 2 as 28 3 18 b E it LE ET 1261 76 Is Used on Models 1261 G Is Used on Models 8 C851 12 CA921 12 C821 8 C921 43 NOT SHOWN 10 841 18 C911 14 C821 10 CA921 12 CB841 20 CA911 16 C811 CA911 16 CAB21 18 C811 14 C911 18 CA821 20 CAB11 16 C911 24 CAB11 TWIN SEAL MODEL 1261G amp 1261 76 OPERATOR DIS ASSEMBLY 18 Instalihe bal bearing 25 the upper stem 9 and secure with nut 15 20 Apply a smooth coating of Permatex Form A Gasket to of operator housing 1 Unscrew 37 and remove indicator fag 9 21 Fasten the gear housing 2 the operator housing with cap screws 35 2 Remove indicator shaft protector 22 and CAUTION NOTE THAT THE SHORT CAP SCREW 728 IS 1 and oe cor 7 INSTALLED DIRECTLY UNDER THE CENTER OF THE WORM move upper stem 22 gear housing 2 with grease up o the of he worm gear 5 5 Remove upper bearing 25 23 Apply a smooth coating of Permatex Form A Gasket to surface of gear housing 2 6 Remove cap screw 34 handwheel washer 16 handwheel 11 and woodruff 24 Install grease seal 24 in gear housing cover 7 Side cover
7. 72 10 726 Screw properly entered rear bearing cup 28 34 728 728 728 Screw DECUS T a ap 35 729 729 729 Screw Cap 14 Apply a smooth even coating of Permatex Number 30 to bearing cover boss on gear housing Fasten bearing 8 in pace with cap srews 32 Be sure to install 38 7214 7244 7555 Screw the plastic shims between gear housing and bearing cap 37 72 21 7221 72 21 Screw 18 insat uarn goar e in ger easing wt sale opening 38 743 744 7928 Screw Set 16 Apply Form A Gaske o top of operator housing 1 Place gear housing 2 wh assembled parts on of Rousing guiding wom gear foy over 39 748 746 Screw ey 19 in upper stem 3 40 79480 75 130 Nut Hex 5 mg sc vor go M 41 76612 76612 76 612 Fitting Lube sien gear housing 2 to operator housing 1 with cap screws NOTE THAT THE SHORT CAP SCREW 33 IS INSTALLED DIRECTLY UNDER 42 78 406 78 406 Ring Retaining THE CENTER OF THE WORM SHAFT 7 43 78404 78 408 78 408 Ring Retaining 18 Fil gear housing 2 wth grease up to of worm gear dA Ss4is 95 413 83 413 Cover not available separately GENERAL VALVE COMPANY TWIN SEAL MODEL 12616 amp 1261 76 Cross Section Exploded View 37 ri
8. But stall torque does not represent same damaging concern MANUALLY OPERATED VALVES Manually operated valves operated locally allow access to thelr manual body bleed valves which may be vented slightly to relieve this pumping ac tion as well as thermal build up f this center cavity cannot be vented to the atmosphere for environmental or safety reasons the may be required Optionally a manual body bleed alone may be acceptable Problem Isolation valve closed Symptom Valve stalls as it unseats Solution Open isolation valve close only to repair Relief check valve Close isolation valve installed backwards seat valve bleed and drain valve remove reverse reinstall close bleed open isolation valve Check valve plugged Same as above but foreign material replace or clean Tubingfiping leaking Loose fitingsipple Close isolation valve damaged bleed close vale bleed and drain valve repair as required open isolation valve close bleed In order to check that your bleed system is properly working install ob serve a proper pressure gauge upstream of the valve Seat the General Twin SealTM verify integrity Hook up a hand pump with proper pressure gaug ing to the manual body bleed With the hand pump reservoir full of compat ible fluid open MBV begin pumping slowly observing body cavity pressure Note it should not exceed upstream pressure by more than 25 PSI If this is 5
9. Install the indicator shaft 12 up through both stems and secure with nut 43 in the bottom of the lower stem rete Preece 1 6 Install O ring 23 in the lower housing 25 Oper Shield 2 7 Place the roller 21 in the side opening of the lower stem 4 A liberal 28 65401 Grease Seal 1 application of grease wil hold itin place 27 66424 Ball Bearing 1 8 Place the stems with bearings 28 bearing retainer and roller 21 assembled 28 66455 Bearing 1 down through the top of the upper housing unti he lower of the two bearings 29 66 454 Bearing Cone 2 rests on the shoulder in the upper housing 30 65463 Bearing Cup 2 9 Apply a smooth even coating of Form A Gasket o the surface ofthe guide pin 31 9914 Sper Hands 1 boss on the lower housing 10 Insert the guide pin 16 to fully engage the slot in the lower stem and fasten wih cap 33 33 725 Screw 2 11 the gear key 20 in the keyway of the upper stem 728 Screw 1 12 Place the tapered roler bearing cones 29 each end of the worm shat 7 35 7226 Cap Screw 8 wit the large diameter of the cone taper against each shoulder 38 7254 Cap Screw 12 13 Assemble the cups 30 on the cones 37 7387 Screw 12 14 Install the worm shaft inthe gear housing 38 73125 Cap Screw 1 15 Apply a smooth even coating of Form A Gasket to motor adapter mounting 39 746 5 1 surface f the gear housing 16 In
10. PIPE PLUG INTEGRAL BUSHING BOLTED GLAND 222 71 STUD L 75 HEX NUT ___ 72 CAP SCREW ___ 6 GLAND SHOWN 907 OUT OF POSITION 62A O RING amp 62D BACKUP RING 76 PIPE PLUG SHOWN 907 OUT OF POSITION 62 B O RING 63 PACKING 2 BONNET un m 49 GASKET 62C O RING 4 These units do not require discrete bushings due small hydro seating 1 BODY forces incorporating a slightly larger 5 SLIP operator however alows bolted glands to be employed 3 LOWER PLATE 76A PIPE PLUG 49 GASKET 62C O RING GENERAL VALVE COMPANY BUSHINGS ONE GLAND POSITION SHOWN PIPE PLUG SHOWN OUTOF j POSITION Qe PIPE PLUG 1 76B PIPE PLUG 16 C811 ONLY CAP SCREW Typical Arrangement of O RING 198 C921 6 cott 12 BACKUP RING 2 6 6921 12 C821 GLAND 2 851 6 41 tz O RING 2 87 12 coat sTuD 2 cen 8 421 14 HEX NUT 2 6921 8 14 BONNET 2 con 8 14 cort GASKET C91 8 16 cat O RING 4 6821 16 1 PACKING a
11. al ner nd secure wh socket head cap eren 8 10 Remove the worm gear 6 and key 19 Install the grease seal 25 in the gear housing cover 9 Slide the cover over the indicator shaft 12 and secure to top of gear housing 2 with cap screws 11 and remove the gear housing 2 625a 154 6 7856 12 Unboltand remove the guide pin 14 18 Pulithe upper stem 4 with lower stem 3 roller 20 lower bearing 27 and indicator Part Part No Part No Description shaft 12 out through the top of the housing 1 I the bearing is snug in the housing 1 21 422 21 623 21 623 Housing Operator instal the worm gear with its key on he upper stem upside down hub up Tum the ear counter clockwise to raise the lower stem as far as possible Insert a 17 diameter bar through the two holes in the bottom of the housing Using a pipe wrench 22 440 22 555 22 555 Stem Lower on the gear hub tum clockwise and jack bearing clear of housing 2 x 14 Remove the setscrew 38 and push the indicator shaft sub assembly 12 out trough 22 439 22554 22 554 Stem Upper 2 21 408 21 405 21 443 HSG Gear 3 4 the bottom ofthe lower stem 5 41 406 41 401 41 401 Pin Drive 6 7 8 15 Remove the lower stem 3 ftom the upper stem 4 23 402 23 408 23 406 Gear Worm 16 Remove the retaining ring 43 and lower bearing 27 from the upper stem 24 404 24 4
12. are 23 54416 64 418 Plastic Pug 5 Install the indicator shaft sub assembly 10 up through both stems EI aor Seal i 6 Install 21 in housing 1 learing 7 Place the roller 48 in the side opening of the lower stem 4 26 66 411 66 411 Ball Bearing 2 8 Place the stem assembly into the housing 1 taking cae that he roller 48 27 66 465 66 465 Bearing Cone 2 is aligned wit the roller groove in the housing Push the assembly down untl 28 66 466 66 466 Bearing Cup 1 the lower bearing 26 rests on the shoulder in the housing 29 69 414 69 414 Spinner Handle 4 8 Apply a smooth even coating of Permatex Form A Gasket to the surface of the 30 722 722 Screw guida pin boss on the housing 1 31 723 723 Cap Screw 2 10 stm anti 2 are Cap Screw 3 11 Place gear key 18 in keyway of upper stem 3 33 72 7 727 Screw 1 12 Install tapered roller bearing cup 28 in rear bearing recess of gear housing 2 34 72 8 72 8 Cap Screw T wih large dameter of taper facing out 35 7243 7243 Screw 2 13 _ Install tapered roller bearing cup 28 and cone 27 on handwheel end of worm 36 72 21 72 21 Screw shaft 6 37 7328 746 Screw 1 14 Install worm shaft 6 in gear housing 2 Make certain that rear bearing cone 7 35 7328 74 32 Ss Scrow 5 contest apps 39 76 412 76 412 Lube Fitting 1 16 Apply a smooth coating of Permatex F
13. of housing 1 500 H Is Used on Models 10 Install O Ring 15 in housing cover 5 and secure to housing 1 2 0841 27 0921 with cap screws 22 37 41 3 11 Install the handwhee 8 and key 11 4 4 12 Install the bearing retainer nut 27 and tighten securely FCT 821 13 Install grease seal 19 and bushing 12 in top of upper stem 2 6 11 14 Install stem protector 18 15 Install indicator flag 6 and secure with screw 26 not available separately Ss 9 TWIN SEAL MODEL 376G amp 501G Exploded View mm Cross Section Section B B 501 G Is Used on Models C841 2 C921 841 3 C911 376 G Is Used on Models 3 2 0811 C821 a 821 4 C921 3 11 21 6 CA811 U TWIN SEAL MODEL 376G amp 5016 OPERATOR DIS ASSEMBLY Remove the indicator pin 34 and pull the indicator stem 8 up through the gear housing 2 Remove the stop screw 35 and dowel pin 93 Drive out the upper coupling pin 32 and remove the coupling 10 Remove the cap screw 29 washer 11 handwheel 9 and key 12 Remove the four cap screws 27 and the gear housing cover 7 Remove four cap screws 27 and lift off the gear housing 2 It may be necessary to turn
14. phone maintenance contracts startup service and service training seminars General Valve Company PCC Flow Technologies Company Main office 800 Road Brookshire Texas 77423 Tel 281 934 6013 800 926 2288 Fax 281 934 6058 TolHree 800 765 2266 _http Wwww general valve com CIO GENERAL VALVE Buleinis2 Alspectcaons and materials are subject change witout note GENERAL TWIN SEAL GVM REZILON VFR GV BEST VALVE BEST VALUE WHEN LEAKS MATTER SEAT AND RESEAT HGO GOSP AND SAFETY BLEED ar registered trademaris of Genera Valve Company VITON And TEFLON aro registered trademarks of DU PONT Printed in the USA Pav 32000
15. the 2 54 740 upper stem 2 into the lower stem 4 such that the drive pin 3 pen the upper stem comes against the shoulder at the TOP of the lower s pe nr eg stem and the detent recess in upper stem is exactly in line with the roller opening in lower stem This operation may require several attempts as the threads are multiple start and do not always assemble correctly with the first try 3 Install the indicator shaft assembly 7 up through both stems Align the detent hole in the indicator disc with the threaded hole in the lower stem and fasten with set screw 25 Set screw must be below Cross Section 625 Is Used on Models the outside surface of the lower stem 2 0851 27 C941 4 Install O Ring 16 in housing 1 27 0861 47 941 s Place roller 14 in opening of lower stem liberal application of 37 67 con grease wil hold it in position 37 0861 6 921 Place the stem assembly into the housing taking care that roller is 27 0841 aligned with roller groove in housing Push entire assembly down 47 C851 until bearing rest on shoulder in housing 6 7 Apply a smooth even coating of Permatex Number 3D to surface of 8 811 guide pin boss on housing 1 10 11 8 Insert guide pin 14 with detent pin 10 and spring 13 to fully engage slot in lower stem and secure with cap screws 21 9 Apply a smooth even coating of Permatex Number 3D to top surface
16. to prevent trapped body pressure from exceeding the working pressure of the vale Therefore a relief system is required to prevent pressure buildup in the body cavity HANDWHEEL REPOSITIONING On gear operated models the handwheel postion may be changed as follows A Place valve in full open positon Remove gear housing cap screws C handwheel to further open the valve ths wil gear housing Continue until handwheel comes to desired position and gear housing mounting holes are aligned D Replace gear housing mounting cap screws Be sure short cap screw is inserted below worm shaft MAINTENANCE The Twin Seal Valve requires no day to day maintenance however there are some services which may be needed occasionally Annually drain plugs in the lower plate should be removed and the residue flushed and drained from the lower plate In cold cimates before freezing weather sets in any possible collection of water below valve plug or plug trunnion shouldbe drained out through the lower plate drain plugs Keep the valve operator housing of lubricant to displace and prevent moisture from accumulating and freezing The operator is provided with a grease fiting Lubricant shouldbe injected with the Seal Valve in the open positon only Under ordinary conditions a few pumps of he grease gun semi annually is sufficient Use lium 12 hydroxy stearate or lithium base molydisulfide grease b If applicable tempor
17. 04 24 403 Shaft Worm 26 401 26 401 26 401 Cap Bearing OPERATOR ASSEMBLY 9 26 413 26 403 26 403 Cover Gear Housing 10 26 412 26 411 26 423 Carrier Bearing 87 on pper dira fA 11 27 406 27 406 27 406 Indicator Flag This bearing is assembled such that the wide surface of the inner race seats on he upper stem shoulder 12 27 429 27 435 27 435 Indicator Shaft Install retaining ring 43 to lock the bearing in place 18 28 404 28 402 28 402 Handwheel NOTE The retaining ring comes against narrow surface of inner race 14 41407 41498 41 498 Pin Guide 2 Aoplyibersl coat of grease to all surfaces of the upper stem below the bearing Thread 5 the upper stem 4 into the lower stem 3 such that stop pin 5 in the upper stem 15 77 403 41 410 41 410 Pin Coupling comes against shoulder at the TOP of the lower stem and the detent recess in upper 16 75 462 42 401 42 401 NutHex stem is exactly in line wit the roler opening in lower stem This operation may require 17 44 401 44 401 44 401 Washer sons as he threads are mutiple start and do not ahways assemble as 45 402 45402 145 402 Key Woodi 3 Install the indicator shaft assembly 12 up through both stems Align the detent 19 45 403 45 406 45 406 Key Straight must be Pe ele stare everson 20 403 48413 48413 Roller 4
18. 25G 7516 amp 7556 Cross Section Exploded View 27222222 625 G Is Used on Models C851 2 C941 C861 4 C941 6 G C851 Catt 861 C821 C851 C821 Cait 0 BIS 9 AY 5 5 N 751 G Is Used on Models 6 C841 8 cont 8 C821 10 Coit 107 C821 129 755 G Is Used on Models 14 0811 e C851 6 C941 8 CA841 Em n LT TWIN SEAL MODEL 6256 7516 amp 7556 OPERATOR DIS ASSEMBLY 20 Install bearing 27 in bearing carrier 10 NOTE The widest surlace of the outer Tace goes against the shoulder in the bearing carier foa Som piike 4 d 21 Applya smooth even coating of Form A Gasket over lop sur ace of gear housing Unbot and remove gear housing cover 9 ruinas 22 bearing cater 10 on top of gear housing 2 Install wo cap screws 36 2 E n 3 tao bon t 180 apart to temporarily align the bearing carrier They need only be partially 8 8 din Remove upper retaining ring 43 pue Famer say wen 3 andy 18 28 lel kt 14 suppa eteni ndn reg uth wench noe ro rbor ard fom eng eap 0 i CAUTION DO NOT DAMAGE PLASTIC SHIMS T 8 Screw he worm shaft 7 Front bearing cone 26 and cup 28 and rear beating 25 install stem protector 24 2 wi ane out win be vom stat 28 canthenbe
19. Align the detent hole in the indicator disc with the threaded hole in the lower stem and fasten with set screw 18 Set screw must be below the outside surface of the lower stem 6 Place the roller 9 in the side opening of the lower stem A liberal application of grease will hold the roller in position 7 Place the stem assembly into the housing taking care that roller is aligned with roller groove in housing Push the entire assembly down until the bearing rests on the shoulder in the housing 8 Install the retaining ring 25 in the top of the housing 1 9 Install grease retainer 10 in handwheel 6 and place handwheel and key 7 on upper stem Install bushing 8 and grease seal 14 in handwheel nut 19 Screw the nut on the upper stem and tighten down on handwheel securely 10 Install stem protector 12 11 Install indicator flag 5 and secure with screw 17 not available separately TWIN SEAL MODEL 500 amp 625 Exploded View OPERATOR DIS ASSEMBLY 1 Unscrew 26 and remove indicator flag 6 2 Remove the stem protector 18 3 Remove bearing retainer nut 27 4 Remove the handwheel 8 and key 11 het her ieee 5 Unbolt and remove the housing cover 5 T peas Dum nem 6 Unbolt and remove the guide pin 9 with detent pin 10 and spring 13 MESEM 7 Pul
20. GENERAL TWIN SEAL Operation Maintenance amp Service Manual Included in the following pages you will find assembly drawings exploded views parts lists assembly tips operational descriptions and routine maintenance requirements for the current design of the General Twin Seal TABLE OF CONTENTS VALVES Integral Bushing Retaining Ring Gland Integral Bushing Bolted Gland Bushings One Gland Bushings Two Glands Bearings Dual Retention Bearings Internally amp Externally Retained Bearings Internally Retained w Two Glands Qa sOnn OPERATORS Model 375 H BLEEDS Understanding the Bleed System MISCELLANEOUS Operation Maintenance 20 Parts 20 Where to find us GENERAL VALVE COMPANY INTEGRAL BUSHING RETAINING RING GLAND 6 GLAND 62 O RING 62B O RING 63 PACKING 2 BONNET 49 GASKET 62C O RING 72 CAP SCREW 76 RETAINING RING Typical Arrangement of 2 0811 C821 811 21 The smallest of the twin seal valves do not require discrete bushings due to minimal hydro seating forces within the valve Also note that due to the size of the operator the gland is held in by a retaining ring backed up by the operator housing 76B PIPE PLUG 1 5 SLIP 4 PLUG 49 GASKET 62 O RING 3 LOWER PLATE 76A
21. Install O Ring 22 in housing 1 21 6243 6213 6213 O Ring 5 Place roller 20 in opening of lower stem A liberal application of grease will hold it 22 62 22 62 209 62 209 O Ring in position 23 64 405 64 402 64 402 Plastic Plug 6 Place the stem assembly into the housing taking care that roller is aligned with roller groove in housing Push entire assembly down unt bearing rests on shoulder 24 64491 66411 64411 Protector in housing 25 65 401 65 401 65 401 Seal Grease 7 Apply a smooth even coating of Permatex Form a Gasket to surface of guide pin 26 58 401 66 401 66 401 Bearing Cone boss on housing 1 8 Insert guide pin 4 to full engage slot in lower stem and secure with cap screws 27 66 412 66 410 66 410 Bearing Ball 81 28 66 458 66 458 66 458 Bearing Cup 3 Place gear key 19 in key way ot upper stem 29 69 414 68 414 69 414 Handle Spinner 10 instal tapered roler bearing cup 28 in rear bearing recess cf gear housing 2 with large diameter of taper facing out 30 TED p 564 19 install tapered roller bearing cup 28 and cone 26 on handwhee end of worm 31 724 724 724 Screw shaft 7 Place bearing cone 26 opposite end wit large diameter of taper 725 725 725 Serew agaist shaft shoulder 12 Instali worm shaft in gear housing Make certain that rear bearing cone has 33
22. LE CREASE AT LEAST 66 BEARING SEMI ANNUALLY TOP amp BOTTOM 62F O RING 71 STUD 75A NUT 26 BEARING RETAINER 73 SOC HD CAP SCREW 62C O RING 62G BACKUP RING 4 PLUG 26 BEARING RETAINER 73 SOC HD CAP SCREW 62C O RING 82A O RING 82D BACKUP RING 76B GREASE INJECTOR 763 ELBOW 76C NIPPLE 6 GLAND 626 BACKUP RING 75A NUT Typical Arrangement of 76D NEEDLE VALVE 76G NIPPLE 8 C851 ELBOW 10 C851 76H NIPPLE 76E BUSHING High pressures require hydrostaticaly balanced plugs and two glands GENERAL VALVE COMPANY Exploded View 3 Description E Operator Housing TT 24 Lover 16 40 Fag prj Tun zr Koy 145 145 T Sese iare 00 08 H spia Pate 77 Grease Sea cA Bal Being TH Sew TH EET D TT Tute Fii TOT ie Pa TH TS Res ny THW ting Ring 375 Is Used on Models C811 2 C821 F 1 E E a F CAB21 OPERATOR DIS A
23. RINGS DUAL RETENTION venr nce GREASE NOP a BOTTOM Typical Arrangement of 12 C941 seen 14 Cai Mec 16 C921 run d _ BEARING RETAINER ORANG 20 21 CAR ORINA 20 C841 2 I farrearscrew GASKET Or NLY B 20 CA911 7 packa 20 92 T E 247 1 cm 24 can 24 C821 GASKET 20 CAST ONLY 24 21 28 0811 E 30 C821 GREASE AT LEAST SEM ANNUALLY TOP BOTTOM T 1 As valve size increases 50 E does the plug load therefore these sizes pease econ require bearings VENT WHILE INJECTING emona GREASE OP BOTTOM T macur Typical Arrangement of 36 CAB11 This valve requires bearings The inner bearing retainer is slighty different than the one above GENERAL VALVE COMPANY arm GREASE AT LEAST SEMI ANNUALLY TOP amp BOTTOM BEARINGS INTERNALLY amp EXTERNALLY RETAINED 250 ADAPTER 76E NEEDLE
24. SSEMBLY 1 Unscrew 17 and remove indicator flag 5 2 Remove the stem protector 12 3 Remove the handwheel nut 19 handwheel 6 key 7 and grease retainer ring 10 4 Remove the retainer ring 25 and pull out the upper stem 2 with lower stem 3 bearing 15 roller 9 and indicator shaft sub assembly 4 out through the top of the housing 1 5 Remove set screw 18 from bottom of lower stem and push indicator shaft sub assembly 4 out through the bottom of the lower stem 6 Separate the stems and remove the retaining ring 24 and the bearing 15 from the upper stem 7 Remove grease seal 14 and bushing 8 req d from top of upper stem 2 8 Remove O Ring 11 from inside of housing 1 OPERATOR ASSEMBLY 1 Install O Ring 11 in housing 1 2 Place the bearing 15 on the top of the upper stem 2 Install retaining ring 24 3 Apply a liberal coating of grease to all surfaces of upper stem 2 and inside and outside of lower stem 3 4 Thread the upper stem and lower stem together such thatthe drive pin 22 in the upper stem comes against the shoulder at the TOP of the lower stem 3 and the detent recess in the upper stem is exactly inline with roller opening in the lower stem NOTE This operation may require several attempts as the threads are multiple start and do not always assemble correctly with the first try 5 Install the indicator shaft sub assembly 4 up through both stems
25. VALVE NIPPLE ELBOW GREASE 7 VENT WHILE INJECTING eR Ius 2 mr d Man 1 2 30 UU 760 GREASE NUECTOR FEK NIPPLE 8780 ELBOW 268 BEARING RETAINER suo NUT PIPE PLUG SLIP REM 46 SUP PAD E LOWER PLAT asa SUPPORT 710 srun 766 NEEDLEVALVE 520 BACKUP RING c GASKET 5 suP 7 1 Boor 1 86 BEARING 524 BACKUP RING 2 asc GASKET 1 GASKET TM STUD NUT 2 Typical Arrangement of 10 CB841 GREASE AT LEAST SEM ANNUALLY 10 941 TOP a BOTTOM 12 3 76D antAsE BEARING RETAINER These valve sizes require bearings 6 GLAND VENT WHILE INJECTING 7B stu 3 GREASE TOP 75B NUT 63 PACKING 760 NEEDLE VALVE 76G NIPPLE 62E O RING 62H BACKUP RING 2 62F O RING 49 GASKET 62A RING L 62D BACKUP RING 62B O RING 2 BONNET 76B GREASE INJECTOR 763 ELBOW 76c NIPP
26. arily remove ABBV cover and guide Liberally apply grease in this area semiannually If at any time the body bleed should indicate a leak which cannot be stopped with ordinary force on handwheel no cheaters necessary this may be corrected by one of the following Operate valve through open close cycle while fluid is flowing to flush out valve body After several flushing attempts close Twin Seal Valve and check body bleed again If body bleed stil indicates valve leakage proceed to b GENERAL VALVE COMPANY b If your valve is supplied with a system itis possible that the relief valve may be leaking Check tis by temporarily closing the line isolation valve I the leak stops repair or replace the reef valve If this is not the case the sips need inspection c To inspect or replace slips the line must be drained Then place Twin Seal valve in open postion check body bleed valve for zero line pressure and remove lower plate lower plate can be driven by closing valve inserting wedge and then opening valve again Sips can be removed from plug and inspected or replaced if damaged Be sure to save the old sips and retur to General Valve Company for exchange credit Itis recommended to replace the lower plate O ring and gasket any time lower plate is removed and slips are replaced If lower plate is not accessible for replacing seating sips the valve operator and bonnet can be removed Chec
27. during normal operation the automatic BLEED HOLE located in bonnet on all valves except as noted below portion ofthe relief sys 9 uw tem reliet check valve willbe defeated The DOWNSTREAM outlet ofthe relief valve AN THROAT TAP would close when clos ing the isolation valve standard This bleed valve installed in the relief system is opened after the Twin Seal is mi ermal Ferre The remaining compo nents of the bleed sys tem i e tube fittings system disc closed Seal effective ness can be immedi ately evaluated after allowing a few seconds for stabilization of cavity vol ume due to entrained air or gas The bleed valve must be closed before the Twin Seal is reopened nipples pipe fittings etc are not functionally involved in how it works but may be involved in why it doesn t work which will be discussed later o Electrically powered actuators or motor operators are configured normally to bypass ignore the opening torque limiter as the valve just begins unseating Ifthe motor operated General Twin Seal has experienced any thermal ex pansion the pressure in the body cavity may have increased significantly above line pressure see figure below which would hydrostatically cause unseat load resistance Worse yet as these slips are pulled inwardly by the ascending plug the trapped body cavity volume is squeezed like an accor d
28. em nut 21 Install insert and set screw into upper stem nut fe Tam worm shaft courte ciodiwire to ful open postion 22 Filthe gear housing with grease up to the top of the worm gear 2 Rem veset sore 38 end indicator eg 11 28 Apply a smooth even coating of Form A Gasket around top surface of the 3 Remove the stem protector 24 4 Unbolt and remove the gear housing cover 8 24 Install the grease seal 26 in the gear housing cover 8 Slide the cover over 5 Remove the set screw 39 and upper stem nut 17 the indicator shaft 12 and ball bearing 27 and secure tothe top ofthe gear ree by e 10 CAUTION DO NOT DAMAGE THE housing wih cap 36 and remove bearing cap 10 PLASTIC SHIMS UNDER MOTOR ADAPTER 25 in on protector 24 and secure indicator flag 11 in place with set 8 Remove the worm shaft 7 and taper bearings consisting of cones 29 and cups 30 1500 G 9 Remove worm gear 6 and 20 No Description Reqd 10 Unboltand remove the gear housing 8 74572 Lower Housing 1 11 Unbolt and remove the guide pin 16 2 A57 Upper Housing 1 12 the upper stem 5 and lower stem 4 with bearings 28 bearing retainer 3 21573 Gear Housing 1 and roler 21 through the top of the upper housing 2 If bearings are ies le Ser 1 snug in the upper housing remove the upper and lower stems with the roller through the bottom of the l
29. ion PRESSURE BUILDS AS A RESULT OF THERMAL EXPANSION OF A TRAPPED VOLUME OF LIQUID 29 ue paessuneD INDEPENDENT OF BODY CAVITY PRESSURE UNSEATING BEGINS CAVITY PRESSURE une PRESSURE REMAINS CONSTANT This pumps the body cavity pressure even higher adding directly to the ther mal expansion pressure until something gives such as 1 The slip seals retract or 2 The motor stalls or 3 Something breaks or 4 TheDTRreleves Since our slip seals are so dependably bubble tight and motor stall may be as high as 6 times maximum rated torque remember the torque limiter is out of the unseat circuit we see that electric motor operators MUST have AU TOMATIC pressure protection which is as shown previously exactly what the DTR does best Torque switch settings on electric actuators should be set higher on the opening direction than the closing direction ESPECIALLY IMPORTANT ON MOTOR OPERTED VALVES UNSEATING CONTINUES 1 SLIPS RETRACT SUFFICIENTLY FAR TO DISLODGE SEALS FROM BODY PRESSURE EQUALIZES CONCERNS OF OTHER TVPES OF RCTURTORS Other remotely power operated valves i e hydraulic pneumatic DC etc may display stall problems during unseati no automatic pressure protection is installed therefore DTR is required in these applications also
30. k body bleed for zero line pressure before removing bonnet and replaced from the top of he valve 3 stem packing needs replacement it can be changed as follows Remove operator as described in 4 below b Remove packing gland and replace inner and outer O rings and backup ring Remove packing rings and replace carefully 4 Replace packing gland e Replace operator as described in 4 4 To change operator Shut down ine pressure 8 Close Twin Seal Valve extra tightly Open bleed valve for zero pressure when removing operator 4 Drive out coupling pin towards guide pin boss Remove housing mounting bots and Ift operator 0 Replace new operator in reverse order insert coupling from same side as guide pin boss 9 Close bleed valve fh Check operation of valve Genuine factory replacement parts are available from General Valve Company which inventories original equipment parts Slips O rings and packing are packaged in kits that make ordering simple Be sure to specify size series part number on slip and type of resilient seal material in your order of replacement slips To perform on site maintenance a mechanic should keep slip and soft good on ste Most kts can be shipped from stock typically within 48 hours ater receipt of order General Valve Company also offers major valve remanufacturing emergency repairs money saving reconditioned slips technical assistance by
31. l the upper stem 2 with lower stem 4 roller 14 bearing 20 pmax ag and indicator shaft 7 out through the top of the housing 1 Ifthe me rt eet bearing is snug in the housing replace the handwheel and key Turn eee the handwheel clockwise to raise the lower stem as far as possible Tea ea Insert a 3 8 diameter through the two holes in the bottom of the spem em t housing Turn the handwheel clockwise and jack the bearing clear of o ea ea Bag the housing m am se 8 Remove the set screw 16 and push the indicator shaft sub em 94s assembly 7 out through the bottom of the lower stem eee xs A 8 Remove the lower stem 4 from the upper stem 2 was ring 10 Remove the retaining ring 20 and bearing 20 from the upper stem 11 Remove the O Ring 16 from the inside of the housing and grease ear EN seal 19 and bushing 12 f red from the top of the upper stem 2 2 840 60 m 14 74 8 OPERATOR ASSEMBLY a e tee 1 Place the bearing 20 on upper stem 2 Install a retaining ring 30 eer to lock bearing in place 3 Te 2 Apply a liberal coat of grease to surfaces of upper stem 2 below 3 pm pH sm the bearing and to all surfaces of the lower stem 4 Thread
32. ll worm gear 6 in gear housing with hub down Toward smallest opening Apply a smooth coating of Permatex Number 3D to top fange of upper housing Place the gear housing with assembled parts on top of the upper housing guiding the worm gear keyway over the key 20 in the upper stem and fasten to the upper housing with cap screws 38 Install ball bearing 27 over upper stem and secure with nut 17 22 28 24 25 26 Fill the gear housing with grease up to the top of the worm gear Apply smooth even coating of Permatex Number 3D around top surace of gear housing Install the grease seal 26 in the gear housing cover 8 Slide the cover over the indicator shaft 12 and the ball bearing 27 and secure to the top of the operator housing with cap screws 35 Install the stem protector 24 and secure the indicator flag 11 in place with set screw 39 Install the handwheel 13 with key 19 washer 18 cap screw 34 and spinner handle 31 1276G litem Description 1 Lower Housing 2 Upper Housing 3 21505 Gear Housing 4 22589 Lower Stem 5 22534 Upper Stem 8 7 8 23 481 Gear 24 425 Worm Shaft 25 487 Gear Housing Cover 9 26488 Bearing Cap 10 25 489 Bearing 17 27 406 Indicator Flag 12 27541 Indicator Shaft 18 28432 Handwheel 34 41473 Drive Pin 18 41476 Coupling Pin 36 41480 Gui Pin 17 42408 Nut
33. ller on the left side lace the upper stem operator stem and roller which have been assembled together see steps 2 amp 3 into the operator housing 1 down through the stem bushing 14 and cam roller bushing 13 until the shoulder of the upper stem 4 is against the bearing 23 5 Install bearing 23 in the gear housing 2 Install the O Ring 21 inthe top cof the gear housing 2 6 Install the tapered roller bearing cup 24 in the recess of the gear housing with the large diameter of the taper facing out 7 Install tapered roller bearing cup 24 and cone 25 on the handwheel end of the worm shaft 6 Place bearing cone 25 on the opposite end of the worm shaft with the large diameter of the taper against the shaft shoulder Apply liberal amount of grease to all parts Install the worm shaft in the gear housing Make certain that the rear bearing has properly entered the rear bearing cup Install O Rings 17 and 20 in the gear housing cover 7 and assemble to the gear housing 2 with four of the cap screws 27 Run the screws in just enough to keep parts in place but do not tighten at this time 10 Install O Ring 19 in the top of the operator housing Place the gear housing onthe operator housing with the worm gear on the left side as viewed from the top same side as the roller and fasten with four of the screws 27 NOTE Worm shaft must be moved out slightly to allow parts to assemble
34. move the guide pin 16 the upper stem 5 and lower stem 4 with bearings 28 and roller 21 out through the top of the upper housing 2 If bearings are snug in the upper housing remove the upper and lower stems with the roller through the bottom of he lower housing 1 Unbot the upper and lower housing and remove the bearings with a suitable puler Separate the upper and lower stems and remove indicator shaft assembly 12 OPERATOR ASSEMBLY 10 12 13 14 15 16 17 18 19 20 2 Install the two bearings 28 at the top end of the upper stem 5 NOTE These are radial thrust bearings and must be installed such that the widest surfaces of the inner race ways are back to back INCORRECT INSTALLA TION WILL RESULT IN SERIOUS DAMAGE Apply a smooth even coating of Permatex Number 30 to the bottom flange of the upper housing 2 and fasten to the lower housing 1 with studs 32 and nuts 40 The dowel pin 43 is a press fitin the lower housing and a slp fitin the upper housing function is to properly align the roller grooves Apply coating of grease to all surfaces of upper stem 6 and lower stem 4 Thread the two stems together such that the drive pin 14 in the upper stem comes against the shoulder at the top of the lower stem and the detent recess in the upper stem is exactly in ine with the roller opening in the lower stem This operation may require several attem
35. o the DTR relief has been verified Ss on ation Maintenance Service Manual OPERATION The General Twin Seal Valve is a non ubricated resent seal plug type valve which has mechanical means of freeing the plug before itis rotated from the closed to the open positon In opening the valve the plug is raised thus retracting the seating segments or slips through their tapered dovetail connections Only ater the sips are fly retracted perpendicularly from the body seat 5 the plug rotated to the open position Conversely in closing the valve the plug and sips are rotated freely with no seal o body contact unt the slips positioned over the ports Then the plug is driven down between the sips and the tapered surfaces wedge out the slips positive upstream as well as downstream shut off For maximum upstream sealing Do not back off Do not use cheaters The small Twin Seal Valves are handwheel operated and require up to 3 turns to or close Up to 2 turns expand or retract the slips while litum rotates the plug Large valves operate in similar manner except that they have enclosed weather proof worm gearing At the top of the valve position indicator flag shows the exact plug position It appears in line with the fow when the valve is open and perpendicular to the fow when the valve is closed Since Twin Seal valves hold bubble tight for ease of opening in quid service itis important
36. on media pressure vessel rigidity and presence of entraned gas it is known that dangerously high pressures will build up in liquid fled positive shut off valves Therefore the General Twin Seal in liquid service requires a pressure relief device The differential pressure thermal relief system is one such automatic device and should be included on every automated valve The diferential pressure thermal relief DTR system is arranged as shown below A variety of components are used in the DTR As shown here one can see that the relief valve mounted at the tee outlet on the bonnet pipes An isolation valve installed in the upstream throat tap is also included on the standard DTR It must be left open to permit relief system to relieve pressure upstream stream throat of the valve The standard re lief valve is set to open at 25 PSI on all valves regardless of working pressure With the over pressure o up RELIEF VALVE N The isolation valve will be used only for main tenance and trouble shooting which will be explained later TEE MANUAL BLEED Valve is to be CLOSED valve closed the relief valve will open at 25 PSI above upstream pressure This system 1 functions only when the valve is closed 2 VALVE manual body bleed valves included on the questreau General Twin Seal oN ONLY FOR REPAIR If closed
37. orm A Gasket to bearing boss on gear 40 78 405 78 405 Retaining Ring 2 housing 2 Fasten bearing cap in place with cap screws 30 Be sure to install 41 78 407 78 407 Retaining Ring 1 the plastic shims between the gear housing and the bearing 42 93 413 93 413 Cover 1 17 Instal worm gear 6 gear housing 2 hub down onard smalest ering 43 26712 Adapter 1 18 Place the gear housing 2 wih assembled parts on top ofthe operator housing guiding the worm gear keyway over key 18 in upper stem 3 Cross Section Exploded View ra 1276 G Is Used on Models 10 C851 16 C921 16 CAB41 20 CB921 20 21 24 CA821 30 0811 6 ll OPERATOR DISASSEMBLY 10 12 13 Tum handwheel counter clockwise to full open position Remove set screw 39 and indicator flag 11 Remove the stem protector 24 Unbolt and remove the gear housing cover 8 Remove the bearing retainer nut 17 and ball bearing 27 Remove cap screw 84 washer 18 handwheel 13 and key 19 Unbolt and remove the bearing caps 8 and 10 CAUTION DO NOT DAMAGE THE PLASTIC SHIMS UNDER FRONT BEARING CAP 10 Remove worm shat 7 and taper bearings consisting of cone 29 and cup 80 Remove worm gear 6 and key 20 Unbolt and remove the gear housing 3 Unbolt and re
38. over indicator shaft 10 key 17 and ball bearing 25 and secure to top of operator housing with cap screws 32 1 vee remove bearing cap 8 CAUTION DO NOT DAMAGE PLASTIC 25 Install the indicator shaft protector 22 26 Install the indicator flag 9 and secure with screw 37 8 Screw out worm shaft 8 Front bearing cone 27 and cup 28 and ear bearing 27 install handwheel 11 with woodruff key 17 washer 16 and 34 cone 27 will come out with the worm shaft Rear bearing cup 28 can then be Install handwheel 11 with woodruff key 17 washer 16 and cap screw 34 removed from gear housing 1261 G 1261 7G 9 Remove the worm gear 5 and key 18 litem Part No Part No Description No hi L 1 21 621 21 621 Operator Housing 1 18 Unbotandremore the guide pin 13 2 21 518 21 518 Gear Housing 1 18 upper stem 3 with the lower stem 4 roler 19 two bearings 26 and 3 22 552 22 552 Upper Stem 1 indicator shaft 10 out through the top f the housing 1 Hf the bearings are snug 4 22553 22 558 LowerStem 1 inthe housing install the worm gear 5 wih its key 18 on the upper stem upside 5 23 472 23 472 Worm Gear 1 down hub up Tum the gear counter clockwise to raise the lower stem as far as 6 24 428 24 428 Worm Shaft 1 possible Insert 117 diameter bar through the two holes in the bottom of the 7 26513 28513 Gear Housing Cover 1
39. ower housing Unbot the upper and lower housings 5 22509 Upper Stem 1 and remove the bearings with a suitable puller 6 2941 Worm Gear 1 13 Separate the upper and lower stems and remove the nut 43 and indicator 7 24 425 Shaft 1 shaft 12 8 26515 GearHousngCover 1 9 26488 Bearing 1 OPERATOR ASSEMBLY 10 26 48 Bearing Cap 1 Install the two bearings 28 and bearing retainer at the top end of the upper 31 27406 Indicator 1 stem 6 NOTE These are radial thrust bearings and must be installed such thatthe widest surfaces of the inner raceways are back to back INCORRECT LE 1 INSTALLATION WILL RESULT IN SERIOUS DAMAGE aE lone Br 1 2 Apply a smooth even coating of Form A Gasket to the bottom flange of the 2 upper housing 2 and fasten to the lower housing 1 with studs 32 and 18 32410 CouplingPin 1 nuts 40 16 41 474 Guide Pin 1 3 Apply a liberal coating of grease to all surfaces of the upper stem 5 and lower 17 7541 Nut 1 stem 4 18 44401 Washer 1 4 Thread the two stems together such that the drive pin in the upper stem 19 5402 Key 1 comes against the shoulder at the top of the lower stem and the detent recess 20 45444 1 in the upper stem is exact ine the roller opening in the lower stem zi 45408 1 This operation may require several attempts as the threads are multiple start 28 68 D 9 1 and do not always assemble correct with the frst tr E ES eee 1 5
40. pts as the threads are multiple start and do not always assemble correctly withthe first try Install the indicator shaft sub assembly up through both stems and secure with the pin 44 in the bottom of the lower stem Install O ring 23 in the lower housing 1 Place the roller 21 in the side opening of the lower stem 4 A liberal application of grease wil hold itin place Place the stems with bearings and roller assembled down through the top of the upper housing until the lower of the two bearings 28 rests on the shoulder in the upper housing Apply a smooth even coating of Permatex Form a Gasket to the surface of the uide pin boss on the lower housing 1 Insert the guide pin 16 to fully engage the slot in the lower stem and fasten with cap screws 33 Place the gear key 20 in the keyway of the upper stem 5 Place the tapered roller bearing cones 29 on each end of the worm shaft 7 withthe large diameter of the cone taper against each shaft shoulder Assemble the cups 30 on the cones 29 Apply a smooth even coating of Permatex Number 3D to the surfaces of the bearing retainer bosses on the gear housing 3 Fasten the blind bearing 8 in place with cap screws 36 Install the worm shaft 7 in the gear housing Install the O Ring 22 in the bearing cap 10 and fasten in place with screws 86 Be sure to re install the plastic shims between the gear housing and the bearing cap Insta
41. stall o ring 22 in the bearing cap 10 and fasten to gear housing with u m E screws 36 Be sure to re install the plastic shims between the gear housing iting and motor adapter 4 76 70 Pipe Plug 1 17 Install worm gear 6 in gear housing with hub down toward smaller opening 43 75441 Nut 1 18 Apply a smooth even coating of Form A Gasket to the top flange of the upper 7221 Capscrew 30 housing 45 75442 Coupling Pin Nut 19 Place the gear housing with assembled parts on top of the upper housing 46 32452 Spacer 1 guiding the worm gear keyway over the key 20 in the upper stem and fasten not available separately to the upper housing with cap screws 38 GENERAL VALVE COMPANY This specification addresses the proper functioning trouble shooting and repair of the General Twin Seal differential pressure thermal relief DTR bleed system When the General Twin Seal valve is seated and completely filed with a liquid any slight variation in temperature due to the sun s rays or ambient thermal fluctuations will cause drastic changes in body cavity pressure resulting from thermal expansion Valves filed with 330 fuel oil have exhibited a 75 PSI increase in pressure with a temperature rise of only 1 F Putting this into perspective a normal daily 30 F swing in ambient temperature may cause an increase of body cavity pressure of 2250 PSI While results vary under actual service conditions depending
42. the worm shaft counterclockwise to back the worm clear of the gear while liting off the gear housing The worm shaft 6 and the tapered bearing cup 24 and cone 25 on each end may now be removed from the gear housing 2 The operator stem 3 upper stem 4 bearings 23 and roller 16 may now be lifted out of the operator housing NOTE The cam bushing 13 and stem bushing 14 are a press fit in the operator housing and should not be removed Should the cam bushing require replacement the operator housing must be returned to the factory 3766 5016 litem Part Part No Description Req d 1 21 583 21 555 Operator Housing 1 2 21584 21 554 Gear Housing 1 3 22524 22 508 Operator Stem 1 4 25560 25525 Upper Stem 1 5 77465 77 464 Pin 1 6 24451 24 445 Wom Shaft 1 7 26 632 26 580 Gear Housing Cover 1 8 27 545 27 504 Stem Indicator 1 9 28441 28 42 Handwheel 1 10 32 476 32 469 Coupling 1 11 44 465 44 453 HandwheelWasher 1 32 45 31 45 131 Key T 13 46 557 46 501 Cam Bushing 1 34 46558 46 502 Siem Bushing 1 15 46559 PlotBushing 1 16 48 405 48 101 Roller 1 17 6271 6234 O Ring 1 18 62 83 6270 O Ring 1 19 62 398 6279 O Ring 1 20 6291 6291 O Ring 1 21 82 371 62 339 O Ring 2 22 54424
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