Testing Safety and Relief Valves Online and In-Place

You use what is called a gag. It is in the shape of a horse shoe and has a jacking bolt. You take the top cover off the safety valve and slide the gag over the top of the exposed safety valve. The bottom of the gag has a foot on each side that catches on the bottom of the valve, you then start screwing the jacking bolt down until it touches the spindle of the safety valve. You then tighten the jacking bolt down just firm enough that the spindal will not move when the presure is increased. So if you had three safety valves 1) set at 100 PSI and 2) set at 105 psi and 3) set at 108 Psi, you would run up the vessel till the first safety pooped. This would give you the popping presure of #1, next you would gag #1 and run up the vessel until #2 popped, again you would leave #1 gagged and gag #2 and run up the vessel until #3 popped. This is the way to test the popping presure live on a vessel.

Hello, can you post any web link where is possiable to buy this "gag".

Generally the manufacture of your safey vave will have gags for purchase, also some boiler companies that service presure vessels will lend or rent gags.

the most important safety valve manufactures have gags, usually pneumatic, in order to test safety valve on site without dismantling. Someone are portable systems the other has a fixed control panel.

Both require electrical supply(for solenoid valves) and pneumatic (for force).

Basically the equipment has a head located in the upper part of the valve instead of valve cap end, with a diafragm vessel threaded on the valve steam. when you introduce air into de vessel the force against the diafragm open de valve and with a system pressure very low you can open the valve. Additionally a solenoids valves control de pressure and inlet an exhaust air With a portable PC you can perform the test outside the risky area

For further information consults for instance the webs of Crosby, Sempell or Leser manufacturers

Steam and gas service valves can be tested online in-place using Team Industrial Services. www.teamindustrialservices.com Contact 757-613-9213 jkessinger@teamindustrialservices.com

Dear Mr. theiumy,

You have asked " How can we test the safety and relief valve online and in place?"

Is it the testing for its capacity or is it for FINDING AT WHAT PRESSURE THE VALVE LIFTS and RELEASES STEAM and WHAT PRESSURE THE VALVE CLOSES.

If it is for its CAPACITY, it cannot be done at site easily.

If it is for FINDING AT WHAT PRESSURE THE VALVE LIFTS and RELEASES STEAM and WHAT PRESSURE THE VALVE CLOSES, use a TOOL known as GAG. One valve will be made not to open by GAGGING TOOL and the other Valve will lift and close. Note the Pressure readings of opening and closing and set as you like, and remove the Gag tool.

Then fix the GAGGING TOOL in the other Valve i.e. 2nd valve and repeat the excercise for the valve gagged earlier, and set to your requirement.

Normally the GAGGING TOOL WILL BE SUPPLIED BY THE SAFETY VALVE MANUFACTURER.

DHAYANANDHAN.S