Gas Seismic Shutoff Valves, Excess Flow Valves (EFV), and Building Codes

[iOne]

Oh my, it seemed like a simple topic but it's not.

In my area for multifamily a seismic shutoff valve must be installed on the customer side of each gas meter, during certain retrofits, or when an insurance company "asks politely". One per unit, plus common gas.

I have an owner who would prefer the shutoff valve be on the distribution pipe: after the shutoff but before any meter. They want to inspect the whole building after a quake prior to turning gas back on to any unit, and want to centralize and perhaps lock the shutoff restoration control. And install one valve, rather than dozens.

LA code SEC. 94.1217.0. SEISMIC GAS SHUTOFF VALVES provides that "A single seismic gas shutoff valve or excess flow shutoff valve may be installed upstream of the gas utility meter at the discretion of the gas utility."

Yet: CPUC decision 01-11-068 November 29, 2001 allowed Southern California Gas Company to prohibit "upstream of the meter" emergency shutoffs, on what seemed like cost grounds. SCGC did not want the cost or liability of a valve they owned, nor did they want the liability or cost of inspecting such vavles. A protest by a startup company making inexpensive shutoffs was denied. (See https://docs.cpuc.ca.gov/published/Graphics/11562.pdf )

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So where does this stand now?
Are there utilities and cities allowing EFV's or SSV's on the common gas pipe?
Have you installed one?

Are any utilities using pre-shake "USGS ShakeAlert®" type systems to halt gas flow, or create a negative pressure in gas lines to eliminate the need for millions of individual shutoffs? Earthquake Early Warning systems are operational in Mexico, Japan, Turkey, Romania, China, Italy, Taiwan, etc.... is there any code movement regarding switching to utility scale shutoffs?

 

[Joe.B]

Utility companies are usually responsible for everything up to and including the meter. It makes sense that they would prefer it to be after, not their problem. Suggest that they ask about getting one main meter (utility owned) followed by the single gas shutoff valve and a bunch of sub-meters (privately owned). I don't know if that's done for gas, but it's done for water and electricity, so why not?

 

[iOne]

It makes sense that they would prefer it to be after, not their problem. Suggest that they ask about getting one main meter (utility owned) followed by the single gas shutoff valve and a bunch of sub-meters (privately owned). I don't know if that's done for gas, but it's done for water and electricity, so why not?

There was a proposal in the CPUC documents to allow customers to buy the utility owned meter, flipping the liability/ownership equation.

In the LA fires apparently gas kept flowing: to the point where some distribution lines had to be dug up to be capped, as no appropriate shutoffs were found. Seems like a bad "solution".

 

[Paul Sweet]

Individual shutoffs are still necessary in case one unit is uninhabitable for repairs or alterations, otherwise the gas to all units has to be shut off.

 

[iOne]

Individual shutoffs are still necessary in case one unit is uninhabitable for repairs or alterations, otherwise the gas to all units has to be shut off.

That's not a factor.

Millions on millions of apartments are on cluster gas meters, with no existing quake shutoff. That's a solved problem. On the other hand quake shutoffs introduce a host of new problems. Someone bumps things with a trash can? That's a new service call for a handperson. Some ex is mad? They can turn off the heat to any apartment and never be caught.

 

[iOne]

Suggest that they ask about getting one main meter (utility owned) followed by the single gas shutoff valve and a bunch of sub-meters (privately owned). I don't know if that's done for gas, but it's done for water and electricity, so why not?

we have local rules that prohibit private submetering.
But maybe we could get one overall master gas meter from the utility, utility owned,
which is a non-revenue meter. that would create a boundary between the utility and customer property and resolve the problem.

 

[iOne]

My local utility will install an EFV on the common gas:

Installing an EFV involves construction work and digging of the service line (please note it is possible natural gas service will be interrupted to install the EFV). Any paving or concrete work required as part of the installation will be included in the cost estimate, and the restoration of pavement or concrete will be scheduled at a later date.

While an EFV can restrict the flow of natural gas, it will not
protect against household appliance malfunctions, small
punctures in underground pipelines or pipeline damage from
natural disasters such as earthquakes or flooding.

The cost to install an EFV at your home or business could range from
$2,500 to $6,000, or more, based on specific site conditions. Certain
eligibility limitations may apply.

https://www.pge.com/content/dam/pge/docs/outages-and-safety/safety/ExcessFlowValves.pdf

 

[ICE]

PG&E says that the cost to install the valve is $2,500 tp $6,000. The valve is approx $200 so somebody is making too much money. I don’t know a lot but I see that one model is reset after an earthquake by inserting a screwdriver and turning it.

So thankfully the valve worked during an earthquake because the stove gas connector ripped loose. The owner resets the valve and an hour later, his stuff is all over the neighborhood.