Question about Inline Air Compressor In Line Check Valve 12x12npt

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I am replacing a check valve on my air compressor. It is 1/2 in pipe threads on both ends with a large brass cap on the side. I cannot blow through the valve. I am curious to know if it has an adjustment on it. How much pressure should it take to get air through?

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A check valve typically would have about a 1psi cracking pressure. I doubt your can blow that hard though. If you want to know, connect a air supply to a regulator with a gauge to the check valve. Slowly turn up the pressure regulator until air passes through the check valve. Pay attention to the flow direction. Usually a check valve doesn't have an adjustment to adjust this pressure, however some are self venting, to remove pressure from the compressor, when it shuts off. If yours doesn't have the small copper line to the pressure switch, then it may be this type.

Posted on Jul 22, 2010

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There is no adjustment.

Btw, I’m available to help over the phone in case u need at

Posted on Jul 22, 2010


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Hot water heaters are a collector of sediment. The proper care includes flushing out the collected debris through the low side drain faucet. The problem is the faucet is not designed correctly to carry out the needed task. If you are handy... turn off the water and gas or electricity to your water heater. Relieve the water pressure through the temperature/pressure relief valve on the side of the water heater tank. Once pressure is relieved close the valve. Determine if you have a 1/2 inch or a 3/4 inch diameter drain valve hole in the side of the tank where the drain valve is located. The drain valve can be removed with channel lock pliers, an 8 or 10 inch adjustable wrench, or a small 8 to 10 inch pipe wrench. Water will leak out the threaded hole while the valve is out. If everything is closed maybe 2 cups of water will leak out of the hot water tank as you check drain valve thread size. DO NOT take your time checking thread size. After you know the pipe thread size go to the hardware store ( Home Depot, Lowe's etc) purchase a short nipple (1 1/2 to 3 inch depending on available space) and a ball valve (brass) due to the water temperature. You will also need a brass adapter for pipe thread to garden hose thread (male both ends). This adapter goes into the ball valve to allow for the connection of a garden hose. Connect the pipe and valve together using the correct pipe thread sealant and install in place of the original plastic drain valve. Install pipe to hose adapter using thread sealant. With the ball valve in place turn the water back on. Gas or electricity back on. Connect a garden hose to the ball valve. Place the other end of the garden hose in a safe area as hot water and debris will be expelled through the hose. With water on, Gas or Electricity on and the relief valve closed actuate the ball valve to the full open position for approximately 3 seconds then close the valve. Repeat the open and close of the ball valve three times. Observe the debris that emptied out of the garden hose. You may be surprised at what you see. If the water runs clear, disconnect the garden hose the task is completed. You can wait until the following year to repeat the process. Your pipe and valve are now a part of the water heater, they may remain in place. Put the hose away.

Aug 31, 2015 | Water Water Heaters

1 Answer

Compressors kicks breaker at 60 psi.

This is usually caused by long extension cord, leaking check valve or weak capacitor. Most likely leaking check valve. Easy to check, run compressor for a couple of minutes and shut off. Listen for air leaking from pressure switch or at the intake filter. If leaking, let out air and remove check valve and look for debris stuck under the valve seat. To find the checkvalve, follow the air discharge tube from the head of the compressor to the tank. You should find a brass or chrome valve threaded into the tank. If check valve is not leaking, suspect weak capacitor or long cord (motor shop will test cap for free). Good luck

Apr 02, 2013 | Craftsman Air Tools & Compressors

1 Answer

26 gallon model 919.167700 160 psi 1.6 hp Bottom of the compressor has a threaded air relief valve that cannot stop the compressed air from escaping. The compressor is new?! I tried using teflon tape...

if it's leaking from the center ,try loosening it let air blow out & tigthen .--- if it's leaking from the theads try tigthening it some more without breakage //////// this valve is the same as a metal radiator petcock with pipe threads that are tappered // return the compressor if still under warranty or try pipe dope -- check for crossed threads--buy new petcock from auto parts store .....a street elbow & 4'' of pipe & quarter turn vavle from the home depot ( or similer supply store ) works nicley as a replacement / this way you can reach the valve to drain the water with out laying on the ground.--------------1/4 pipe thread i think .

May 31, 2011 | Craftsman Air Tools & Compressors

1 Answer

I have a Rheem 40 gallon hot water heater which is about 2 years old. The drain valve drips a bit while the hot water heater is heating up the water and then stops once the water is heated up. What is the...

When you say drain valve, do you mean TP valve?
Two different things: -drain valve and -TP valve

-Drain valve is located near bottom of tank and has hose thread on end.
-TP valve is brass and is located on side of tank tank near top on , and has a pipe that runs down within 6" of floor, or pipe goes into a drain pipe. DO NOT CAP OFF TP VALVE because this is safety outlet that prevents extremely hot water from rupturing tank.

1) If drain valve located near bottom of tank is leaking, it can be capped with a garden hose cap from hardware store-home center. Thread cap on end of drain valve.

2) If TP valve is leaking.
a)Turn down thermostats on water heater
b)Replace TP valve
c) Install expansion tank on incoming cold water line
Buy expansion tank at hardware-home center-plumbing supply and tee straight out from cold water line and attach expansion tank. About the size of small football.

4) Mythbusters blows up a water heater for your enjoyment U-tube
Video shows that extraordinary pressure is needed to blow up heater.
This event has only been reported once in past 10 years that I have read, and it blew out side of home. Stats for this type event don't exist in insurance company records, so you are safe - just don't cap off TP valve.

5) Add a comment for more free help.
Also take advantage of fixya phone service.
For a price, expert speaks with you over phone while you work on heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

Jan 16, 2011 | Rheem 40 Gallon FVR NATGAS Low WATER...

2 Answers

I have an Eagle River compresoor it is 5 or six gal but put oil in it and ran for fifteen minutes like says turned it back on but blows air out bottom of tank out hole that has threads but has no valve or...

You are missing your discharge tap, or drain valve(there are several names for it. It is usually 1/4 or 1/8th national pipe thread. I would be shocked if you found a supplier for the exact Eagle River part because I just looked for 15 min and found nothing by way of a breakdown or parts list for any model. The good news is, once you determine the thread size, you can generally install any drain valve assuming there is clearance between the compressor in its resting position, and the floor.

In my shop I use RolAir because they are fairly cheap but work well. This is actually a Emglo part.

EMGDC18 DRAIN ****, BRASS, 1/8" 2.35 LIST COST
EMGDC14 DRAIN ****, BRASS, 1/4" 2.10 LIST COST

Follow this link for a Rol-Air dealer near you(type in your zip code) and they should be able to UPS out the one you need. I hope this helps.

Dec 05, 2010 | Eagle Air Tools & Compressors

1 Answer

Leaking water heater, the spout on the side is dripping water all over the basement floor.

You can try fixing this problem by putting a garden hose cap over end of valve.
Cap has a washer.
If leak is bad, you need to replace drain valve.

If the valve is brass, then drain water heater and put a wrench on valve and unscrew.
Buy replacement brass valve from plumbing supply or Lowes-HomeDepot


If the valve is plastic, then expect it to break off when trying to remove.
If it breaks off, then you can carefully drill out the stem, and then burn it out with a torch and use a 3/4" pipe nipple to try to cut a new thread.

If water heater will not drain ... put washing machine hose on water heater valve - run water hose between washing machine hose and outdoor spigot and turn on water for 10 seconds to break open clog inside water heater.

Oct 25, 2010 | Rheem 40 Gallon FVR NATGAS Low WATER...

1 Answer

Compressor pumps up fine but then leaks air just below the relief valve. out of a small factory hole in a brass fittting and goe down till compressor starts again.

When the unloader leaks as you describe indicates that the check valve is leaking. Easy to check the condition of the valve. Follow air discharge line from compressor head to tank. The brass or steel fitting that threads into tank is the checkvalve. Remove all air from tank and remove large inspection cap to reveal the teflon seat. If it is cracked or swollen you will need to replace the valve. Parts available at Good luck

Sep 25, 2010 | Hitachi EC12 Portable Electric 2hp Air...

1 Answer

Angle Stop Installation

the ring is called a "crush" bushing it seals by: (crushing) reducing it's diameter around the supply tube; it can be used only one time as it deforms to seal. each time you remove cut the tube with the old ring off ;put the threaded valve cap with the hole in it (for the tube) threaded side facing the valve on the cut tube; then slip a new ring on the tube and, screw the cap on the valve

Sep 06, 2009 | Plumb Shop Div Brasscraft #453-191 MP...

1 Answer

Pressure switch out of adjustment

Before you adjust the perssure switch, make sure that the intank check valve is not leaking pressure back to the pressure switch after it cuts off at 140psi. The check valve should hold pressure at 140psi. Follow the discharge airline to the tank to find the checkvalve (either chrome or brass with large cap). To check for leaking valve, run compressor till shut-off at 140, then unplug the compressor from wall and remove the 1/4 air fitting at the checkvalve and check for leak. If leaking, replace valve and leave the pressure switch at present setting. You should be good to go. Good Luck with your repair and email if you have questions.

Apr 03, 2009 | Hitachi EC12 Portable Electric 2hp Air...

1 Answer

Need to replace drain valve

The "welded nut" is the pipe fitting into which the drain valve or drain plug is screwed. It's usually brass and the valve or plug can be obtained through Sears or possibly and good harwarde store. Be sure to use pipe sealing compound or teflon tape on the threads when you re-install the valve or plug.


Mar 04, 2009 | Craftsman Air Tools & Compressors

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