Propane Inlet Code Confusion (IRC 2015)

[delaware]

This is for a new piping system to feed propane (LP) to a new gas stove in the State of Connecticut which is governed by International Residential Code 2015 (IRC 2015).

According to "G2421.2 (410.2) MP Regulators":

5. A tee fitting with one opening capped or plugged shall be installed between the MP regulator and its upstream shutoff valve. Such tee fitting shall be positioned to allow connection of a pressure-measuring instrument and to serve as a sediment trap.
6. A tee fitting with one opening capped or plugged shall be installed not less than 10 pipe diameters downstream of the MP regulator outlet. Such tee fitting shall be positioned to allow connection of a pressure-measuring instrument.
7. Where connected to rigid piping, a union shall be installed within 1 foot (304 mm) of either side of the MP regulator.


This corresponds to a setup like this:

My first question is what the heck is the purpose of the union and why do they require it?

If I add a gauge and several PSI of air to the test point, that will expose the regulator outlet to high pressure and is apparently a no-no, and pressure testing a valve is also apparently a no-no. So am I to guess that I somehow have to open and cap the union?

What about pressure testing the sediment trap, just soapy water under load?

 

[MicEd69]

This is for a new piping system to feed propane (LP) to a new gas stove in the State of Connecticut which is governed by International Residential Code 2015 (IRC 2015).

According to "G2421.2 (410.2) MP Regulators":

5. A tee fitting with one opening capped or plugged shall be installed between the MP regulator and its upstream shutoff valve. Such tee fitting shall be positioned to allow connection of a pressure-measuring instrument and to serve as a sediment trap.
6. A tee fitting with one opening capped or plugged shall be installed not less than 10 pipe diameters downstream of the MP regulator outlet. Such tee fitting shall be positioned to allow connection of a pressure-measuring instrument.
7. Where connected to rigid piping, a union shall be installed within 1 foot (304 mm) of either side of the MP regulator.


This corresponds to a setup like this:

My first question is what the heck is the purpose of the union and why do they require it?

If I add a gauge and several PSI of air to the test point, that will expose the regulator outlet to high pressure and is apparently a no-no, and pressure testing a valve is also apparently a no-no. So am I to guess that I somehow have to open and cap the union?

What about pressure testing the sediment trap, just soapy water under load?

It appears that they are requiring a union so that the regulator can easily be serviced. It will also simplify the installation of the piping.

And while your sketch indicates a "pressure test point", the code description only refers to a fitting "positioned to allow connection of a pressure-measuring instrument", and nothing about using it for testing purposes. I would assume that it is for checking the pressure at that point during operation to verify the regulator is functioning properly. While instruments that cannot withstand testing pressures are routinely taken out of lines during pressure testing of piping systems, you should contact the regulator manufacturer to see if testing the regulator at the required test pressure is really a no-no. And I've never heard that pressure testing a valve is a no-no. The valve manufacturers obviously do that routinely.

 

[Twowaxhack]

I test the piping with higher pressure, 15 psi.

Then I install the gas valve, regulators and connect the appliances. Then I test with the normal operating pressure using liquid gas leak detector, I also use a manometer to make sure my regulators are set correctly for each appliances inlet pressure simultaneously.

Sometimes I’ll fire several appliances and make sure my pressure doesn’t drop below the lowest allowable inlet pressure for any of the appliances.

Then I’ll leave my manometer connected and test the entire system. This is a very accurate test……