\"opening\" types of gas valves

Mark J Strawcutter

My (probably incorrect) understanding of gas valve opening types is restricted to:

normal - bang bang
slow - baaaaaaaaaaannnnnnnnnngggggggg bang
stepped - ba---ng bang

are there other types? does a stepped valve only have two steps?

what makes them use one vs another in a given piece of equipment?

Mark

no, I'm not going to mess with one. Just ran across the distinction and was curious.

Gary Fereday

BOOM!

Gas valves are designed to open at the rate ignition occurs at the burner. Old model conversion burners were slow to open so as to not go boom! Many of the older conversion burners and burners of the day had two or more pilots also. newer types were slowed down so that there was a soft light off. Modern two stage gas valves open on high volume and then cut back to low since high lights off better. quicker and then to low volume till the system cannot keep up. Replace gas valves as neat to the original as possible to the opening times. That way you'll not have top go back and settle someone down from a "hard" light.

Duncan

Good question

About all I can offer is an observation: step-opening and slow opening valves seem to be used with propane, on boilers with larger than 100K input.

Betcha Tim has an exact answer.