Cover Image
close this book A training manual in conducting a workshop in the design, construction, operation, maintenance and repair of hydrams
close this folder Session 14: Repair and maintenance (2-4 hours)
View the document Handout 14A: Repair and maintenance chart
View the document Handout 14 B: Repair and maintenance worksheet
View the document Handout 14 C: Maintenance/service worksheet

Handout 14A: Repair and maintenance chart

Attachment 14-A

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

   

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

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

   

clogged snifter valve

clean the snifter valve

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

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.

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

   

insufficient water in the delivery pipe

continue to cycle hydram manually until sufficient delivery head is developed

 

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

 

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

   

clogged delivery pipe.

clean out or back flush

 

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

   

obstruction in drive pipe

clean drive pipe

   

excessive check valve stroke

adjust or replace. check valve stroke limiter

 

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

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