Service Life of Valves in HVAC Systems

[AMM1783]

Hello Folks,

Is there a resource somewhere that has estimated service life for valves used in HVAC applications? Something similar to the table in ASHRAE Handbook - HVAC Applications "Comparison of Service Life Estimate." I am providing recommendations for an existing building fan coil heating water system. The riser isolation valves appear to be original to the building construction (~ 40 years old). A couple have been replaced recently because they were found to be failing. I know there are many factors that influence the actual service life of a valve. But I was just wondering if there was some source I can reference that had estimates for how long before valves may begin to fail.

Thanks!

 

[Artisi]

After 40 years and some are starting to fail - think that might be a good reference to the expected life of the existing valves etc.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[willard3]

Service life will also depend upon the kind of valve, ie, gate valve, ball valve, plug valve......

 

[FacEngrPE]

Artisi's Sherlock Holmes quote is telling - you have some data - the observed failures. To be a bit more sure of your evaluation, have a few valves disassembled, and inspect the inside of the adjacent pipes. Once a piping opened it is usually simple to figure out if the system has a history of good corrosion control, or if it is near the point where frequent failures can be expected.

Fred

 

[LittleInch]

And define "failure".

Stem leak?
Won't seal?
Seize up?
Material failure?

Elastomers will fail eventually but temperature and water quality will have a big impact.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[AMM1783]

Artisi, thanks for your comment. This was my initial thinking. But I was hoping for some literature to have as backup.

willard3, thanks for your comment. Fair point. I assumed different valves have different service life. I was looking for any information even general guidelines.

FacEngrPE, thanks for your comment. I was hoping to avoid the cost of shutting down the whole heating system or using expensive freezing of the pipe just to remove valves that may already be beyond their typical service life. I'm starting to think that might be the best thing to do now.

LittleInch, by failure I mean the isolation valve is allowing too much water to pass through when closed. The maintenance staff cannot shutdown the fan coil risers for servicing.

I guess there are too many factors that determine service life for valves not to mention the many varieties of valves and applications.