GATE VALVES,NUMBER OF ROUNDS CLOSED

[dmreeser]

ACCORDING TO ALL THE INFORMATION I HAVE FOUND, A 24" NRS SPLIT WEDGE GATE VALVE ,150# CLASS VALVE SHOULD OPEN 75 ROUNDS (3X THE VALVE SIZE PLUS 3),I HAVE A H+M GATE VALVE THAT WAS INSTALLED AROUND 1965 THAT ONLY OPENS 51 ROUNDS (2X + 3),I KNOW THAT THE VALVE IS IN GOOD WORKING SHAPE BECAUSE WE JUST PULLED IT APART AND LOOKED AT IT.DOES ANYONE HAVE ANY IDEA WHY THIS VALVE WOULD BE ANY DIFFERENT.

 

[dicksewerrat]

different thread pitch in the valves. In the 24' size it might be time to look at valves with a gear box so maintenance crews can shut it down under emergency situations without power assistance.

 

[1969grad]

AWWA valves a limit on the force required on the handwheel to operate. Seems to me it is 100 lbs but I would have to check to be sure.

So the number of rounds to open various sizes and classes of valves should be a function of the amount of effort required rather than a set number of turns. Hence the use of gear operators on larger size valves.