New jersey BFP required without feeder?

If you manually feed and have shut offs on both sides of your BFP, might as well leave it in.

I think it’s always going to release a little if you don’t keep pressure on both sides.

Many boiler feed instructions say to not leave street pressure 'on', so I guess that means they are all supposed to be manual feed?

With steam and no auto feeder just a manual valve no BFP is required as far as I know. On a hot water boiler with a PRV a backflow is required.

in new jersey a backflow is required on steam boilers feed line . To not have your backflow drip after manually feeding is to not remove pressure from the backflow so the real deal is to have a shut off before and after the backflow and use the out let valve for feeding this is nothing new and most who are not are being penny wise dollar foolish install this way and the customer ends up paying either way just less issues . It may seem uncommon but i have been doing it this way for many years yeah costs me 2 brass nipples and a ips ball valve big deal . this also holds true for house prv they should have a shut off before and after and unless you want o replace leave the pressure on to the valve and just use the outlet valve to shut the water off it will save you replacing the domestic prv being most prv fail after the pressure has been removed especially if a older valve .

clammy

Is your location under a State adopted code? Which one?

There may be local codes that require a specific device

In some areas if the country a non vented dual check is accepted.

This non vented BFD has an ASSE 1024 listing, for example

Your local plumbing inspector should know and be the final say?

it comes down to how the inspector classifies boiler water. If it is filled with potable water, no chemicals, that could be considered low hazard. The ASSE 1024 is for low hazard applications.

Mainly the inspector would be concerned about someone adding a cleaner or chemicals down the road.

Then a BFD with a higher hazard level might apply. Either a vented dual check, or an RPZ with test ports.

Lot of interpretation in accepting BFDs by AHJs. It is rare to see a code book site a specific BFD number.

A 1012 will be a dual check with atmospheric vent.

Intermittent BFD spit can be cured with a swing check upstream, often.

When a fast closing valve creates the shock that causes the BFD to flutter, the swing check catches that force and tends to cancel it.

Of course you will hear that check slap.

A water hammer arestor at the quick valves can help.