Valve types and where to use what...

Jamie Hall

on the main lines, if you should be so inclined to put on a valve, there are a number of designs which work -- but whatever you use, it must be a 'full port' straight through valve -- ball or plug are best. The temptation on larger lines is to use a reduced port valve, as they are much cheaper. However... for most steam heating systems, you are dealing with low pressure saturated steam. The pressure drop through a reduced port valve will condense a good bit of that steam, and you won't get any heat beyond it, even if it is open.

Don't ask how I know...

Michael Wildt

Valve types and where to use what..

Hi,

This question might be considered off topic, but as a homeowner I've always wondered about the following.

There are different types of shut off valves. Some are gate, or ball or offset screw (if that's the correct word).

On my heating system I have a mix of types and while I've read quite a few plumbing DIY books none of them seems to explain what the overall feature is of each type and where they should be used. It seems that ball valves are the superior ones.

On faucet shut off and toilet shut off valves, which hardly get used it always seems to leak a little and I know they are not ball valve design. So is there an age factor to be known as well. Like use a ball valve if you know the shut off is only to be used once in a lifetime.

Just wondering. If this is in any official plumbing certification books etc I'm all ears to learn more.

Thanks
Michael

Ken_40

With the advent of...

Ball valves, all the: OS&Y, globe, stops, waste stops, gate, bullet, balancing, etc. valves - are made suspect with regard to defined purpose and need thereof.

Wafer valves (a/k/a "butterfly") angle stops and steam service valves are all part of the mix of confusion as well.

The question is one that needs to be asked. The answer however, is nebulous at best, vague at worst.

The only correct answer to this valve question is: "That depends."

Exactly what it depends on is the nature of the liquid, pressures incurred and desired purpose of the valve. There are lots of substitutions likely and appropriate and on and on ad nauseum.

The correct answer is in some book somewhere that I have no direct knowledge of a title for.

Perhaps Mr. Holohan may want to author the definitive work in this arena?

It may already exist but other than manufacturer's catalogs; which will inherently lead one erroneously to what they sell - not necessarily what is the ideal valve, an "independently authored work must be out there.

But God knows where. I for one, do not.

Given the depth and breadth of "The Wall" devotees, one can only hope the definitive book does exist, and someone can provide an author and title. Anything dated prior to around the year 2000 C.E. would be suspect. The improvements and new styles, e.g., pump flange sets with built-in ball valves, would render almost any book pre-2000 as "obsolete."

jackchips_2

Ken,

I have a book called:

Stockham Valves and Fittings-Catalog 90, Copyright 1989 which does just what you describe.

It lists just about every type of valve, Stockham, naturally, but it also describes what each type of valve is for and where they should be used and that would apply to any manufacturer.

I do not recall how it came into my posession but it may have been when I was doing design work through a supplier.

Jack

Ken_40

Jack,

I have seen that book and it does what I imply; that being, it does not make a few valves in sizes we would naturally encounter in life. They suggest an alternate be used, simply because they DO make THAT one, but not the correct one.

Nonetheless, a good book is better than no book.

I think (;-o)

Chris_82

Ken and Jack, the size thing is why,...

larger flows, throttling, and media, (steam, process fluids), etc., as the Stockham book implys are the reason for many valve types, as well as non-rising and stem variations in various O,S, &y types.

But for the home owner, cost and cost seem to be the primary determinant. How many of us out there look at the wc h20 valve and always tell the homeowner not to turn it to tightly because we know it's going to fail no matter what we do! Why pay $10.00 for an apollo ball valve when we can install a made in tawane or mexico valve that costs 49 cents? In a home about the only valve that makes a difference is a frost/ ice free for the outside spigot, so you can water your lawn in december, or if you forget to use the inside shut off and open the outside sillcock. As long as it shuts off flow there isn't much difference in home types. As for the "toilet" you can install ball valves, there are a number of decorative 1/4 turn ball valves that work much better for a small cost increase. Ball valves as a rule, quality ones that is, seem to last longer, when it comes time to use them...if you want your valves to last, any type, then exercise them at least once a year, open and close them, and turn off rubber valves with washers in them, lightly, just enough to do the job, because if you crank the heck out of any washeer valve you inevitably damage the valve. The only other concern is on hot water systems, to get a hot water washer, something you won't find at your local box store. But Most quality ball valves have ratings far in excess of what is required in an average home.

Dale

valves

I agree with the other posts, As a general statement I would say the ball valve has become the general default "good" inside valve for water and gas. The new outside valves are mostly water and are the frostproof anti-siphon type globe type. As to the inside ones the pressure rating is the key the 125# wog is used for water and the less expensive 1/2 pound variety for gas. The cheap gas ones are not full port so is the flow is high the more expensive ones should be used. I'm not going into the plastic cpvc valves since I don't use them. Strangely for smaller size = less than 1/2 inch, which I use for nat gas grill lines outdoors the stainless valves are rated for #1200 psi, made in Italy. We have gone to ball valves outside for gas except for small meter valves and where throttling is needed, ball valves are NOT good for throttle use, too wide open too quick. The steam stop valves if used are gate type since the big ball valves that are steam rated are very expensive.

Michael Wildt

Thanks for the world of valves explanation

Hi Guys,

Your comments are awesome. Just what I expected there is more to it. The idea of having Dan Hollohan make a write up sounds like a perfect idea. Hopefully he would be interested in fulfilling this knowledge area.

Much appreciated.

Thanks,
Michael