Tank Valve Training

[Uncle Pug]

Originally posted by Seb
As for "roll off", I have a hard tiume buying this one.

Only happens on the left post when it contacts an overhead...


Or the right post when you are swimming backwards really fast and roll it off on an overhead.

 

[BadFish]

Or the right post when you are swimming backwards really fast and roll it off on an overhead.

I have that problem sometimes.......swimming backwards really fast...

 

[The Chairman]

on how big the sea monster is...

 

[FredT]

It's "Standard Practice" for"open" multiple turn valves in industry and submersibles too. A valve stem can easily freeze against the stop if left in one position. The 1/4 turn off the stop allows the stem to be "worked" a bit allowing any corrosion to be broken free and the valve closed in an emergency. While this is not possible for a "normally closed" valve judicious selection of flow direction can mimimize problems.

The valves in a home that should follow this rule include those service valves supplying water to sinks and toilets, as well as those used to isolate water heaters.

BTW it _is_ possible to swim backwards really fast. I've been chased out of a swim-through on Molasses by a Jewfish that filled the hole. I've also been backed out of a hole by a 10 to 12"diameter moray who thought the bull bug I was chasing belonged to HIM! I let him have it.

FT

 

[pipedope]

There are some valves that are designed to be backseated but these are outrageously expensive and are used only in systems with very dangerous fluids. Nuclear power plants and chemical processing are the main users of these valves.

SCUBA valves, all the way open and back 1/4 turn. Even the US Navy uses this as the standard.