Isolation Ball Valves vs Gate Valves
Isolation Ball Valves vs Gate Valves
(OP)
Both Gate Valve and Ball Valves can be purchased with Class VI shut-off. Are ball valves best to use in a steam process line in lieu of gate valves? Wondering which is best to use in a hospital facility especially since ball valves will open easily and faster than gate valves.





RE: Isolation Ball Valves vs Gate Valves
If piping is large use a warm-up bypass to allow the traps to remove excessive condensate formation at start-up.
RE: Isolation Ball Valves vs Gate Valves
Spirax Sarco's publication "Hook-Ups" is an excellent resource for practical design information on steam systems, and I highly recommend it. I've used it for years, and it has never steered me wrong. It's worth noting that they also have their own line of steam-rated ball valves.
RE: Isolation Ball Valves vs Gate Valves
RE: Isolation Ball Valves vs Gate Valves
RE: Isolation Ball Valves vs Gate Valves
Good design practices are just that. Then there's proper installation. If the facilities involved in the incidents you mention failed to provide adequate trap maintenance or operator training, then that's hardly the fault of the design, or valve selection. Are you seriously suggesting that Spirax Sarco, Apollo and all the other ball valve manufacturers are selling valves that are unsuitable for the intended service? C'mon...
Look at Kirsner's site, and I believe you'll find that pretty much all of the incidents he's investigated involved gate valves. But the type of valve itself was not the source of the problem. It is simply not possible open any valve - including a gate valve - slowly enough to prevent condensation induced water hammer, if conditions exist where it may occur. Kirsner has investigated a number of fatal accidents where operators assumed that the operating technique of slowly opening or "cracking" the valve would keep them safe. Those men are dead because of that erroneous assumption.
Anyone relying on the operational differences of gate, ball or butterfly valves to prevent accidents in steam systems is very much inviting disaster.
RE: Isolation Ball Valves vs Gate Valves