www.hvactechgroup.com - forums

Can someone please explain what 6.23.5 means? Does this mean if an appliance has a Pilot, I disconnect the tube end connected to the pilot burner going from the gas control and purge from the thin tube? Like from a water heater gas control? And if appliance has a continuous pilot I purge using the pilot burner?(without disconnecting anything)?

6.23.5
In the absence of a readily accessible burner
A) an appliance equipped with a pilot shall be purged at the outlet of the pilot valve train after the pilot tubing has been disconnected; or
B) an appliance not equipped with a continuous pilot shall be purged in accordance with the procedure described in Annex H.

Thank you, and any tips on passing the practical would greatly be appreciated. I'm a total newbie in the gas industry.

I think it would be less confusing if they used "continuous pilot" under section A) , instead of just "pilot". That's how I interpret it.

I would imagine they wouldn't want you trying to purge from an expanding, intermittent, interrupted pilot as those have other means of controls that don't allow for proper control of purging.
I also interpret A) as saying you need to disconnect the pilot tube at the end at the valve train just before the part where the pilot flame assembly is located. It seems this method also applies just the same as on natural draft water heater pilot also.  I read it as any situation involving a continuous pilot they want you to disconnect that tube.

We will eventually light the continuous pilot on the appliance when gas is present up to the main valve, but for purging purposes, they don't want it done that way.
I've seen a small explosion under a water heater from a pilot that was lit long enough to allow the safety of the valve to stay lit. But once the main burner came on,  an air pocket from further down the piping came along and it went out while the main burner was letting it flow. it was still quick enough to fill a good portion of the chamber with a new amount of natural gas after that air pocket passed and the safety kicked it off. Person reached in with lighter to try again and BOOM!