
| A training manual in conducting a workshop in the design, construction, operation, maintenance and repair of hydrams |
| Attachments |
Session 14, Handout 14A
Repair and maintenance
|
SYMPTOM |
CAUSE |
REASON |
CURE |
|
impulse valve stops in the closed position |
insufficient rebound |
worn, cracked, or dirty check valve |
clean, repair, or replace check valve |
|
insufficient weight or stroke on impulse valve |
increase impulse valve stroke or weight |
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|
insufficient flow of water into the drive pipe |
check for leaks or obstructions in the supply system. If all the avail able water is going to the hydram, re-adjust the hydram for this flow |
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|
pulsating flow in the delivery pipe |
lack of air in the accumulator |
leak in the accumulator |
repair leak |
|
snifter valve not open enough |
open valve further |
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|
clogged snifter valve |
clean the snifter valve |
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|
reduction in water delivered and air bubbles in the delivery pipe |
too much air entering the accumulator |
snifter valve open too far |
close down the snifter valve slightly |
|
leak in the hydram body between the impulse and check valves |
repair the leak |
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|
impulse valve stops in the open position |
insufficient velocity around the impulse valve |
lack of water entering the drive pipe |
check for leaks or obstructions in the supply system IF all available water is going to the hydram, readjust impulse valve for this flow rate. |
|
Excessive impulse valve weight or stroke |
Either shorten the stroke or lessen the weight. |
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|
hydram won't start |
insufficient back pressure |
check valve not seating properly |
clean, repair or replace check valve |
|
snifter valve open too far |
close snifter until hydram starts |
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|
insufficient water in the delivery pipe |
continue to cycle hydram manually until sufficient delivery head is developed |
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|
poor impulse valve seating |
worn, cracked, dirty or misaligned valve |
clean, repair, replace or align impulse valve |
|
|
lack of water entering the drive pipe |
supply insufficient for hydram |
re-assess installation, possibly install smaller hydram and/or drive pipe |
|
|
leaks or obstructions in supply system |
clean or repair the supply system |
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|
improper impulse valve stroke or weight |
not adjusted correctly |
either change stroke or weight |
|
|
hydram runs but does not pump anything |
obstructed delivery line |
closed delivery valve |
open the valve |
|
frozen delivery line |
apply sufficient heat to thaw |
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|
clogged delivery pipe. |
clean out or back flush |
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|
water hammer pressure pulse absorbed before the check valve |
air accumulation under the check valve because of over- sniffing |
cycle the hydram several times by hand allowing the water to reach maximum velocity before allowing the impulse valve to close |
|
|
hydram runs but the amount of water being delivered is much less than should be expected |
leak in the delivery pipe |
loose fitting or a hole in pipe |
tighten all loose fittings and/or repair any holes |
|
low hydram efficiency |
worn, cracked, dirty, or misaligned check valve |
clean, repair or replace impulse valve |
|
|
worn, cracked, dirty or misaligned check valve |
clean, repair or replace check valve |
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|
obstruction in drive pipe |
clean drive pipe |
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|
excessive check valve stroke |
adjust or replace. check valve stroke limiter |
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|
improperly installed hydram. |
Poor L:D ratio |
change either the drive pipe Diameter or length |
|
|
poor L:H ratio |
change either the drive pipe length or the drive head |
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|
frequency very erratic |
air in the drive pipe |
hole in the hydram body or a loose fitting near the drive pipe connection to the hydram |
patch all holes and/or tighten all loose fittings |