A motorized ball valve to shutoff water to my house

[blackhat]

Every boiler should be fitted with a low water cutoff device. Note should.

[geek2me]

 Please explain why you would have to calculate the gas pressure that would cause a rupture after measuring the rupture pressure using water? 

Gas and liquid pressure are different, as previously stated.

First you said gasses are compressible and liquids are not, now you say they both can be, or not.  Please explain.

No, you are misquoting me.  I hope it was not an intentional misquote to try to support your point.  I said " gas is compressible, water is essentially not compressible" which is true, as a general rule.  Other liquids are compressible, water is colloquially considered to be non-compressible, but will compress a little given enough pressure.  Gas is generally compressible, but some gases reach a point where they will not practically compress further.

Show me a data sheet that says a P/T relief valve on a boiler or water heater will not relieve an over pressure condition if the tank is filled with air? 

That's a little disingenuous - show me a data sheet that says a P&T valve works well as a hammer.

The point is that data sheets list the applications, not the non-applications.  For example this data sheet http://media.wattswater.com/ES-40-140-240-340.pdf specifies the valve is for water and steam and specifies the ASME specs and pressures for both.  They don't list the specs for air since that is not an approved or certified application.  If it were safe or appropriate to use it for air, that would be stated - and the absence of that information is the evidence that usage is not approved.

[jteneyck]

Gas and liquid pressure are different, as previously stated.


No, you are misquoting me.  I hope it was not an intentional misquote to try to support your point.  I said " gas is compressible, water is essentially not compressible" which is true, as a general rule.  Other liquids are compressible, water is colloquially considered to be non-compressible, but will compress a little given enough pressure.  Gas is generally compressible, but some gases reach a point where they will not practically compress further.


That's a little disingenuous - show me a data sheet that says a P&T valve works well as a hammer.

The point is that data sheets list the applications, not the non-applications.  For example this data sheet http://media.wattswater.com/ES-40-140-240-340.pdf specifies the valve is for water and steam and specifies the ASME specs and pressures for both.  They don't list the specs for air since that is not an approved or certified application.  If it were safe or appropriate to use it for air, that would be stated - and the absence of that information is the evidence that usage is not approved.

There's in no point in continuing this exchange.  Hopefully, others will understand fact from fiction.  

John

[geek2me]

There's in no point in continuing this exchange.  Hopefully, others will understand fact from fiction.  

I suggested several posts ago there was little value in continuing the discussion.  At least you were open to learning that much.

Given multiple confirmations in this thread and the PMs I have received, I do think others understand the facts i have posted.