03-10-1999, 10:57 PM #1E7engineerFirehouse.com Guest
Pressure control device as a pressure buffer
How many Departments, use the Relief valve as a pressure buffer? Set it at a desired E.P. and turn up the RPM, just enough for the relief valve to actuate just a little. This is to help prevent pressure surges, at the nozzle??
03-14-1999, 03:26 PM #2kaFirehouse.com Guest
Been doing it for a decade or two. We have a big yellow revolving light on the roof that indicates the relief valve is open we take 1/2 turn more throttle than needed and the rig supplies whatever is needed.
03-14-1999, 09:31 PM #3E7engineerFirehouse.com Guest
KA, I've been an Engineer for over 7 Years. Just took a Pump Class as a Refresher. That's where I picked it up from. I can use any and all new and old tricks of the trade..
03-14-1999, 10:17 PM #4kaFirehouse.com Guest
we've found each turn of the relief valve is 10 psi on a hale, 12 turns equals 150 psi on a waterous and 8 turns for a Darley so you can set the relief valve accurately in the station every time without running the pump.
03-15-1999, 09:22 AM #5Captain HickmanFirehouse.com Guest
We always use our pressure and govenor reliefs on our pumps. We set the desired pressure needed, with water flowning, then set the relief or govenor about 5 psi above that. Then if someone shuts down a line the pressure is dumped back into the pump or the engine slows, which prevents the other line from getting that extra pressure. Having worked on pumps, the biggest problem that I have found with departments, is that they do not use the relief valve system, pilot valve and relief valve properly, or they don't use it at all.
Then when someone is injuried by a loose line or they start blowing pump packings, they call me. Several times, I have had to remove relief valves from pumps and do a major overhaule, due to the valve not being operated properly or correctly used. What is proper? Check the manual which came with you apparatus pump and READ and FOLLOW the manufacture's recommentations....But, do use them..
[This message has been edited by Captain Hickman (edited March 15, 1999).]
03-15-1999, 09:22 AM #6F02Firehouse.com Guest
Another old trick.....Put your relief valve on an exercise program.With the valve off set pressure at 75psi.Back knob clear out and cycle valve on/off.Makes relief valve travel farther than it probably does normally.If you have haard water like us you should start out slow.Maybe 10psi at a time.Don't want it to stick.Although ......better now than on the fireground.
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