MWF FEED
14th May 2020, 01:40 PM
Hi all,
A workmate and j recently swapped air compressors. Mine was a newer but smaller belt driven unit and his was older but larger (too big for his shed) unit made by Clisby.
His unit spent a good part of its life in Darwin. I looked like it has had a hard life but I'm confident that with some TLC it will still be a good unit.
One thing that did concern me was any potential for the receiver to be badly rusted given it's working environment in Darwin. So I decided to do my own hydrostatic testing.
Turns out it's pretty easy to do with a pressure washer. Plenty of YouTube videos including one by Keith Rucker which was very informative.
The plate on the side says the TP is 1650 Kpa and WP is 1100 Kpa that's about 239 psi and 160 psi respectively in the old scale.
Given that my WP will be around 120 psi max and the fact that it is old, I decided to de-rate the test and test only to approx. 220 psi.
I want to know it's reasonably safe but I also don't want to destroy it either.
Process was straight forward. Remove all fittings (I left the non return valve in place as I didn't have a spare 3/4" blank) Fill it with water making sure there is no air left inside and blank off all except for a place for a pressure gauge and the wand attachment.
Start up the pressure washer and adjust the pressure relief valve slightly above the test pressure. Not a huge amount of work for a pressure washer that can do over 3000 psi. Squeeze the trigger on the wand and watch the pressure gauge. The pressure rises very quickly and you need to be on the ball or you will go above your intended pressure and destroy a perfectly good receiver!
When you achieve the test pressure, release the gun trigger, turn pressure washer off and wait about 5 mins.
Look for leaks....
No leaks and no loss of pressure!
Happy with that. Happy myself nor one of my kids will end up wearing it. While it's not a certified test, it gives me some peace of mind.
Simon
https://uploads.tapatalk-cdn.com/20200514/373823b56bb8673e8d9cea255d92dff8.jpghttps://uploads.tapatalk-cdn.com/20200514/b0f602525fd425e3476c0790fdc383a6.jpg
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Read the full thread at metalworkforums.com... (https://metalworkforums.com/showthread.php?t=205038&goto=newpost)
A workmate and j recently swapped air compressors. Mine was a newer but smaller belt driven unit and his was older but larger (too big for his shed) unit made by Clisby.
His unit spent a good part of its life in Darwin. I looked like it has had a hard life but I'm confident that with some TLC it will still be a good unit.
One thing that did concern me was any potential for the receiver to be badly rusted given it's working environment in Darwin. So I decided to do my own hydrostatic testing.
Turns out it's pretty easy to do with a pressure washer. Plenty of YouTube videos including one by Keith Rucker which was very informative.
The plate on the side says the TP is 1650 Kpa and WP is 1100 Kpa that's about 239 psi and 160 psi respectively in the old scale.
Given that my WP will be around 120 psi max and the fact that it is old, I decided to de-rate the test and test only to approx. 220 psi.
I want to know it's reasonably safe but I also don't want to destroy it either.
Process was straight forward. Remove all fittings (I left the non return valve in place as I didn't have a spare 3/4" blank) Fill it with water making sure there is no air left inside and blank off all except for a place for a pressure gauge and the wand attachment.
Start up the pressure washer and adjust the pressure relief valve slightly above the test pressure. Not a huge amount of work for a pressure washer that can do over 3000 psi. Squeeze the trigger on the wand and watch the pressure gauge. The pressure rises very quickly and you need to be on the ball or you will go above your intended pressure and destroy a perfectly good receiver!
When you achieve the test pressure, release the gun trigger, turn pressure washer off and wait about 5 mins.
Look for leaks....
No leaks and no loss of pressure!
Happy with that. Happy myself nor one of my kids will end up wearing it. While it's not a certified test, it gives me some peace of mind.
Simon
https://uploads.tapatalk-cdn.com/20200514/373823b56bb8673e8d9cea255d92dff8.jpghttps://uploads.tapatalk-cdn.com/20200514/b0f602525fd425e3476c0790fdc383a6.jpg
Sent from my SM-G970F using Tapatalk
Read the full thread at metalworkforums.com... (https://metalworkforums.com/showthread.php?t=205038&goto=newpost)