Operating Instructions
Contents
1. The pointer on the meter should show a deflection between scale division 5 and 6 A smaller deflection indicates that the battery requires recharging see main tenance Before starting with the measurements adjust the sensitivity of the Vapophone with the knob The highest sensitivity of the equipment is at knob setting 10 Different trap types produce different sound levels even when steam losses and operating conditions are the same For GESTRA steam traps we recommend for example knob setting 8 for the BK 15 traps and knob setting 7 for the MK 25 traps Testing Position probe pressing gently at right angles to the surface of the steam trap as close as possible to the closing unit of the trap See figures lf traps of the same type are tested take care that the probe is always applied at the same point of the trap body in order to be able to compare the results obtained and also to discover changes when re peating the tests In the case of steam traps operating con tinuously and without steam loss within the pressure range of up to 20 bar 290 psi and with condensate flowrates up to approx 30 kg h 66 Ib h no or only a slight deflection of the pointer on the meter will be seen With increasing steam loss the deflection of the pointer increases The relation between steam loss and pointer deflec tion depends on the type of the steam trap and the point chosen for the measure ment To obtain more ex2. range that permits testing When trapping steam lines and tracers this flowrate range applies as a rule Maintenance The Vapophone does not require any particular maintenance the battery just needs recharging Any defect of the probe or the measuring instrument can only be repaired at our works For this purpose always return the complete equipment i e measuring in strument and probe Recharging of Battery Push coaxial plug of charger into coaxial socket of measuring instrument Then plug charging set into mains socket 220 V 50 Hz Ensure that knob of measuring instrument is in off position 0 on scale Charging time 15 20 hours The capacity is then sufficient for approximately 50 operating hours Overcharging of the battery is impossible provided the char ging set supplied with the equipment is used Important Note The battery must not be charged in hazardous locations Technical modifications reserved G esT R A AKTIENGESELLSCHAFT P O Box 105460 D 2800 Bremen 1 Tel 0421 3503 1 Tx 244945 0 gb d Fax 0421 3503 393 Copyright 1981 GESTRA AG BREMEN Printed in W Germany R 3579e 185
3. Operating Instructions GESTRA Vapophone VKP Ex Issue 1 85 Operation The Vapophone is used to detect sound in the ultrasonic range as caused by flow ing steam The mechanical ultrasonic vibrations are detected by the probe and converted into electric signals which are amplified in the measuring instrument and indicated on a meter The Vapophone is only sensitive to fre quencies in the range 40 to 60 kHz which is typical of flowing steam A false indica tion on the meter caused by ambient noise is thereby largely excluded Description The Vapophone consists of the electronic measuring instrument the probe the connecting cable and the battery charging set All parts are placed in a shoulder strap bag which need not be removed for testing purposes The equipment is intrinsically safe in con formity with classification EEx ib IIC T4 type approval No PTB Ex 84 2063 and is suited for application in hazardous locations Permissible ambient temperature ranging from 15 to 60 C 5 F to 140 F Protection IP 41 Power supply 9 V nickel cadmium battery for 50 operating hours Commissioning Connect probe to measuring instrument with the cable provided The cable is fitted at each end with a BNC plug The connection for the measuring instrument is accessible at the bottom of the bag after loosening the flap Testing of battery Turn knob of measur ing instrument to
4. act measure ments it is therefore necessary to first adjust this relation on the measuring instrument The same applies if the equipment is used with larger condensate flowrates and higher pressures where by the nature of things flow noises are higher so that the sensitivity must be reduced lower values It needs some experience in handling the equipment before useful values are obtained For many practical cases the exact knowl edge of possible steam losses is how ever of secondary importance What is required is often a reference value per mitting the detection with a tolerable expenditure of steam traps no longer operating economically For this purpose the sensitivity should be adjusted to 8 or 7 as explained A continual pointer deflec tion between 4 and 5 scale divisions indicates that the traps should either be serviced or replaced as depending on the trap type steam losses of 1 to 4 kg h 2 2 to 8 8 Ib h can be expected Special Hints It has to be taken into account that ultrasonic sources such as steam reducing stations in the proximity of the steam trap to be tested might falsify the result In this case steam loss might be indicated even though the traps operate perfectly This can be verified by scanning the adjacent pipelines If the deflection remains unchanged or increases this must be attributed to a foreign ultrasonic source At this place of installation testing of the steam traps is
5. therefore not possible Intermittently operating steam traps cause recurrent deflections of the pointer on the meter of the measur ing instrument These deflections might reach the end of the scale Thermostatic traps with bimetallic control or membrane regulators may operate within the pressure and flow rate ranges mentioned either contin uously or intermittently In this case steam losses can be excluded A recurrent pointer deflection therefore indicates correctly operating steam traps Thermodynamically controlled steam traps always operate intermittently over the complete flowrate range mentioned and might thereby cause steam losses which rise with increas ing lift frequency A clear evidence of loss is given by aconstantly large de flection of the pointer on the meter The losses are then however far above the reference values indicated for singling out As far as steam traps with open float are concerned in principle the same applies as to thermodynamic traps Because of the trap system inherent steam losses occur with certainty even during the intermittent working phase of the trap Singling out of such traps in accordance with specific refe rence values to be determined be forehand is practically impossible Ry Before starting with the measure ments an estimation should atleast be carried out with the aid of the technical data of the plant to find out whether the trap flowrate lies within the
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