Flanged 2600
Contents
1. Broady Flow Control Limited BROADY cat es Ere ae Wis fe O A Kingston upon Hull East Yorkshire ast Yorkshire HU3 2DU Telephone 01482 619600 SERVICE MANUAL Series 2500 F Safety Relief Valve Screwed Series 2500 F Safety Relief Valve 1 OPERATION Safety Relief valves are automatic discharge valves and have the function of maintaining the pressure in a circuit below a set limit A Safety Relief valve consists of three main parts Nozzle Which permits the discharge medium to be piped away correctly Disc Which closes the Nozzle discharge orifice Spring Which opposes the force of the medium below the Disc When the force exerted by the pressure of the medium on the disc exceeds the spring force the disc begins to lift The pressure exerted by the discharge medium on the surface of the ring shaped chamber of the disc holder produces immediate opening of the valve The distance of the blowdown ring relative to the disc holder has an effect on the change in the pressure between opening and closing for valves used with gases and vapours For valves used with liquids the blowdown ring must be lowered in such a way as to make it ineffectual 2 INSTALLATION During mounting the Valve Avoid bumping or shaking the Valve to prevent damaging the flange faces and misalignment of the trim Blow through the circuit line on which the Valve is to be installed to remove any foreign matter welding chips e2. ED AIR CONTAINER Fig 1 NOTE Valve shown in illustration is from the Broady 2500 range Series 2500 F Safety Relief Valve VALVE TESTING DATA Tag Number Refer to Name Plate on Valve Refer to Name Plate on Valve Cold Set Refer to Name Plate on Valve Seat Tightness 40 Bubbles min at 90 of the set pressure 4 OVERHAUL Overhaul of the Valve means dismantling it completely to clean every part thoroughly and to decide whether the various parts may be re used adjusted or substituted It is necessary to check that the contact surfaces of the seat and disc area are in perfect condition Should scratching or pitting be present the surfaces must be ground and then lapped 4 1 Lapping the Disc Use a cast iron block with a perfectly smooth and flat surface or a plate glass block of a suitable size For a perfect lap pass the disc across the smooth surface of the block after applying a small quantity of lapping compound using a figure of eight movement Lift the disc periodically away from the block so that the compound may flow from the edges towards the centre 4 2 Lapping the Nozzle Seat Use a cast iron or plate glass block as for lapping the disc and check that this does not tilt to avoid rounding off the edges After spreading the lapping compound over the smooth surface of the block pass the Nozzle seating surface over the block using a figure of eight movement During the lapping operation make sure that there is no foreign
3. ater The seal test consists of raising the inlet up to 90 of the set pressure and checking that the number of air bubbles per minute which pass through the container do not exceed the values shown in the Valve Testing Data table page 5 Should the leakage exceed the values given in the testing data table then consult the table FAULTS IN OPERATION on page 7 3 2 Set pressure For this operation it is necessary to connect the valve inlet to a container in which the pressure may be raised gradually and measured by means of a pressure gauge The test consists of checking that the valve starts opening at the required set pressure refer to Valve Testing Data table Changes outside the stated tolerances must be corrected by varying the spring compression by means of the spring adjusting screw To regulate the set pressure see fig 1 1 Place the valve on the tests stand fig 1 with no pressure on the valve inlet 2 Remove the 3 3 Prevent the disc holder rotating by means of holding the spindle 5 with a screwdriver inserted into the slot at the end 4 Loosen lock nut 14 of the adjusting screw 13 5 Regulate the spring adjusting screw until the desired set pressure is reached Do not allow the disc holder to rotate 6 Reassemble the 3 NOTE For each successive set pressure check the lock nut must be tightened Series 2500 F Safety Relief Valve EQUIPMENT FOR DISC SEAL TEST COMPRESS
4. he revised set pressure 3 Loosening of lock nut on spring 3 Tighten lock nut after re calibrating the adjusting screw valve 4 Poor trim alignment 4 Discharge the valve 2 or 3 times to allow self alignment of the trim Chatter rapid opening 1 Blowdown ring incorrectly adjusted 1 Ensure that the blowdown ring is in the lowest and closing cycle position for liquid service For valves used on gas regulate suitably 2 Insufficient discharge capacity 2 Check that the discharge piping is not too long Check that the valve is not undersized 9 PARTS LIST ea a ee PISS 8 BLOWDOWNRING Z o o O aN S Oe Bae S Oe 2 JOINT CAP S JOINT CLAMPSCREW Tt JOINT PLUG CE CIRCLP o O O PLUG o u iA 8 SPRING Series 2500 F Safety Relief Valve 723 YA 022 a pe Fig 2 also available with Male connections Note Valve illustrated shows Female Type Inlet Part 2 this is
5. lve carrying out the operations listed for disassembly in reverse and taking care to Avoid scratching on the lapped surfaces of the Seat and Disc Clean the trim thoroughly throughout Spread with graphite grease all threads the Adjusting Screw and the Spring Carrier FOR VALVES FOR OXYGEN SERVICE CAREFULLY DE GREASE ALL PARTS BEFORE ASSEMBLY Fit new gaskets To prevent damage to Disc Nozzle faces hold spindle with screwdriver in the slot on the end of Spindle turning whilst compressing Spring Series 2500 F Safety Relief Valve 8 FAULTS IN OPERATION CAUSES SOLUTIONS Leakage 1 Presence of foreign matter between 1 Discharge valve once or twice seat and disc consecutively Should leakage continue disassemble valve and clean trim 2 Scratching or pitting on seat surface 2 Disassemble valve grind and lap seat 3 Valve used with a medium other than 3 Lap seat and disc more finely if the valve specified when ordering originally ordered for liquid service is used with gas 4 Valve not mounted vertically 4 Correct installation Discharge at incorrect 1 Variable back pressure 1 Check that discharge takes place in piping pressure whose dimensions are equal to or greater than those of the outlet connections of the valve and that the discharge piping is free from obstruction 2 Back pressures different from 2 The valve must be re calibrated specified when ordered correcting the spring compression for t
6. matter on the lapped surface or on the block The lapped parts must be carefully cleaned before assembling so as to remove every trace of lapping compound 5 NORMAL MAINTENANCE The most frequent operation to be carried out is a precise check made at regular intervals to observe whether any obvious faults exist in the different parts of the Valve It should be checked first of all that there are leakage s these must always avoided especially when the medium is poisonous highly volatile or very explosive Carry out periodic venting for Valves fitted with lifting devices to check regular operation at least two or three times a year During these tests the pressure must be at least 75 of the full working pressure Series 2500 F Safety Relief Valve 6 DISASSEMBLY 1 2 3 4 5 6 7 8 9 Remove Cap amp Joint 3 amp 32 Measure position of the Adjusting screw 13 and record for re assembly purposes Slacken Locknut 14 and unscrew Adjusting screw 13 Remove Clampscrew 16 Unscrew Nozzle 2 and lift off Body 1 and Joint 31 Lift off the Spindle Valve Lid assembly parts 4 5 7 9 11 amp 35 Lift off the Spring Carriers 17 and Spring 29 Remove Disc 4 from the Disc Holder 7 by tapping Disc Holder firmly onto a clean wooden surface care should be taken not to misplace the Circlip 35 and Ball 11 Unscrew Blowdown Ring 8 from Nozzle 2 7 ASSEMBLY Reassemble the Va
7. tc Clean thoroughly the Valve and Nozzle connections impurities on the Nozzle may damage the Valve Seat during popping Install the Valve in the vertical position only with the inlet downwards Tighten uniformly the bolts of the flanges connecting the Valve to the pipework Use inlet and outlet pipework as short as possible and of dimensions equal to the valve connections Avoid strain on the outlet flange with suitable supports Secure the outlet pipework in order to reduce vibration and to avoid strain on the outlet flange Avoid elbows with small curvature radius on the outlet pipe for high temperature gas and vapour discharge use expansion joints After the Valve has been installed make it pop at least twice to allow automatic alignment of the trim Misalignment may be caused accidentally during transport or during installation of the Valve Series 2500 F Safety Relief Valve 3 TESTS The valves are factory tested before consignment according to the Customer s required specifications detailed in their order It is nevertheless recommended that the following tests be carried out before installation of the valve 3 1 Disc seal For this operation it is necessary to Connect the valve inlet to a container fig 1 in which the pressure may be raised gradually and measured by the means of a pressure gauge Close the valve with a plate in the centre of which a tube is inserted which is immersed a container of w
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