The Stovebolt Site Forums The Shop Area General Truck Talk Heater control valve test?

I have a Ranco H11 heater control valve out of a 47 chev that I need to test? I pulled the entire heater from this truck, the heater core was great just needed to had boiled and cleaned, blower motors work great, so I figure before I pony up $$$ for a new valve I would test this one to see if it still good, any ideas?

some rubber/plastic tubing, hose clamps, a cork will set you up - hook one end up to a garden hose, plug the other, see if it blows up or stands the pressure

Bill

My water preasure runs 80 psi, therostate on the truck 7 psi could that cause a leak that was not there before?

well, ya don't hafta turn the tap on full bore!
it should take say, 15 lbs if it's gonna be good, if it starts leakin at 15-20 lbs it wouldn't have lasted long - there's mainly just a rubber grommet that can be bad, repair kit from NAPA: Napa/Balkamp #BK660-1000 .... and get a regulator on yer house line, a lot of household stuff gives out too soon if pressure is above about 60# alla time

Bill

tap pressure is the same whether you crank it full bore or just a little bit. How about using an air compressor set at 7#, valve should seal tight, then open up and let air (water) flow through.

Wouldn't the proper test be whether the thermostatic feature functions properly...wouldn't it need some hot water going through it. It might not leak, but this might not mean 'it works'. :confused:

Stuart

tap pressure is NOT the same if you don't open the tap alla way, a flow restrictor is a pressure restrictor, put a pressure gauge on it if you don't believe that ... or just try it on your lawn sprinkler

as Stuart sez, if it has the thermostatic capillary tube on it, you might want to check that, but it's the capillary tube that needs to be heated Stoo, and if it's not broken and the guts of the valve aren't corroded, it'll work .... the leaking part is the main problem those things develop, thermostatic or manual, and water is the test, not air - I've rebuilt 2 of them cuz of leaks with the kit I cited above

Bill

Well Red, not to nit-pick too much here but "that's my story and I'm sticking to it". I was assuming the valve would be tested in the closed position. If you connect a faucet to it, crack the tap open, and wait a little while, the pressure in the valve will be the same as the water pressure to your house. And, on a '47 I thought the "thermostatic feature" was pull the knob out if you want it warmer and push it in if you want it cooler.

Hey red58,
I agree that a flow restrictor will reduce pressure on the outlet of the device with flow, but you said plug one end. The pressure will continue to build till it equalizes with whatever the supply pressure is. It doesn't matter how little or much you turn on the valve. That will just determine how fast the flow equalizes.
Jeff

no flow is no flow, low flow is low flow ...whatever ... try the test, it'll work, my city pressure is about 90#, the regulator I put on the building cuts it to 70 measured at the furthest hose tap, my hose turned low, hasn't blown out anything I've tested with it, rancos, cores, or radiators .... maybe someone else has a better suggestion that won't involve hydraulic theory

Waldo, I said either it has a capillary thermostatic control or is manual - pretty easy to see if the valve has the capillary tube or not, which allows it to automatically maintain the temp setting you select - ie: restrict the flow for less heat, or not for more ... this guy could check it for ya , spiff it up, and put in the $5 washer too, shouldn't run more than $100

Bill

When I checked mine, I went "air over hydraulic." I made a setup similar to Bill/Red58's description. I used a bicycle inner tube filled with water connected to one of the sides of the valve. Then I used a bicycle pump to apply pressure. I could regulate the pressure pretty easily this way.

Mine leaked, so I bought a really crummy reproduction (do a search for "TxLaTx crabbing about heater control valves" and it'll probably light up) and re-jiggered it to work. I kept the old one and will play around with changing out the NAPA BK660-1000 grommet that Red58 mentioned later this year.

While I'm on the soapbox, here's another thing I came across: I put my old valve in some 5% vinegar and that baby came out looking VERY good! It dissolved all of that gunk that had been accumulating for 50 years. Just don't leave it stewing for too long or it could end up damaging the metal joints. After pickling it and giving it a good rinse, I lubed the mechanism with moly grease and it seems to work very well. Prior to the dip, it would barely work even after applying a lot of force to it.

Bill

Man, you guys got some pressure up there, no way my 40 y/o pipes would hold that. Ours runs about 40 after the reg, only about 50 psi w/o(straight off the line).

Pascal's hydraulic theory says that pressure in a closed hydraulic system is the same no matter where it is measured. If the hose bib in front of the house has 70 lbs of pressure, the hose bib in the far corner of the house would have 70 lbs of pressure too. When you turned them on, they might have different flows, but the closed pressure would be the same.

Stuart

actually Tx Bill, if you hook it all up and then turn on the water [1/4 turn], you've got "air over hydraulic"

and I'd be sure that folks using original valves from years when the cooling system was zero pressure, on systems that have been modified to 15# don't have valves blowing up
works for me

64fleetside - there was a lot of grief in town when they "upgraded" the water system - some folks didn't pay any attention to the warning that regulators should be installed, blew out old water heaters among other things, but my place was plumbed by me with a 1" feedline for commercial, no problems here with 70#, and great for the apple processing biz
and Stoo, the hose tap in front of my house is before the regulator

Bill

Stoo gives up too...you win! :rolleyes:


Stuart