Where can you get reed valves for lower cost, mass produced, imported air compressors? Or for that matter, if the replacement reed valve, also known as a flapper valve, from the OEM is priced prohibitively, what do you do?

If it is not easy to find replacement reed valves or you don’t like the price, then your only choice is to make your own compressor reed valves.

This page provides a couple of examples as to how you can make your own compressor reed valve with information provided primarily by readers like you, that have successfully made their own.

Table of Contents

Air Compressor Reed Valve Location

The image below identifies the pump parts common to many air compressors including where the typical reed valve is located.

exploded view of air compressor pump - make your own compressor reed valve
Small air compressor pump part diagram

It is necessary to disassemble the compressor pump to find the valve plate or reed valve on a specific model of compressor.

Broken Air Compressor Reed Valve Plate

A broken or cracked compressor reed valve ensures that the compressor would not be able to build pressure satisfactorily. The compressor might just run and run and never build pressure past a certain pressure point, or the compressor might never build pressure at all depending on how damaged the pump reed valve was.

Like almost any new project, the first time you make your own flapper or reed valve will take much longer than if you were making your own all the time. Making your own valve will require a bit of work. It helps if you are handy with tools and enjoy DIY crafts.

When you tear down the pump you will likely find a thin sheet of metal with some type of fingers or flappers. It may look a bit like the following.

closeup view of broken air compressor valve plate
Damaged compressor pump valve

There are many shapes and sizes of reed valves and compressor valve plates, so don’t be concerned if one appears different than the one shown in the image. Recently I’ve been provided another example of a broken reed valve, this one from a Kaeser compressor.

closeup view of broken Kaesar air compressor valve plate
Broken compressor reed valve

Do make sure that it’s the compressor reed valve that is broken, not the compressor valve plate itself. This is not an unusual occurrence due to the high heat inside the compressor pump, and the thousands and thousands if not millions of cycles the reed valves experience as they flap open and closed as the cylinder cycles.

Air Compressor Reed Valve Plate Material

Some folks use a decent quality paint scraper (one that has a large enough blade size) to cut the new valve plate from. The scraper blade is flexible, strong and designed for long term flexing. With it being made out of metal will make it heat resistant.

Another approach is to purchase high carbon spring steel shim stock. Get a supply that is as thick as the original valve plate. If you do a Google search using the phrase – high carbon steel shim stock – you will find a number of sources.

Regardless of your choice in reed valve raw material, just make sure that the material you select is one that remains flexible over thousands and thousands of cycles and is heat resistant. Otherwise, you’ll be tearing your compressor pump down again and building a new valve plate for it a lot sooner than desired.

Air Compressor Reed Valve Plate Fabricating

Using the old valve plate as a template, mark the new material with the correct shape.

Use a scroll-type hacksaw to cut out the valve plate shape from the new stock.

To reduce vibration when cutting the thin spring steel, consider placing the shim stock on a thin sheet of wood first. This provides a base for the metal while you are cutting it, reducing vibration and noise as you cut the spring steel.

Drill comparable sized holes in the new valve plate corresponding to those in the original plate.

De-burr the new valve plate completely to ensure that it’s flat and no small spurs of metal prevent a tight fit over the ports in the valve pump.

Graeme provided the following: “I obtained some .015 shim stock, used marking blue and scribed around my good remaining reed for the outline. I roughed out the shape with snips and finished it using fine files followed by fine wet and dry abrasive paper to round all the edges. The old reed was used as a drill template for the holes. The only small concern I have is the shim stock is softer than the original reed material, but this actually may be advantageous. Only time will tell.”

Install the new reed valve plate into the compressor pump, like Graeme did displayed here:

New reed valve on a compressor pump plate

Another visitor commented on his Central Pneumatic compressor repair as follows:

“On a tear down the cause was clearly visible. One of the reed valves had gotten out of place and broke.

I had some stainless steel structure frame from an old microwave, I traced a form from the unbroken reed.

Cut it out with a dremmel.

The new piece was thicker and I spent 2 full hours (found an actual use for Maury and Jerry Springer!) thinining and straightening both sides on a sharpening stone.

Oddly there was no gasket in the compressor housing. I coated both planes with a layer of Greece and tightened all 4 bolts.

Reinstalled and plugged it in.

On the test both gauges held air up to 60 PSI so I called it a victory and stopped ( before fix didnt hold more than 20 psi). “

Air Compressor Pump Gaskets

Question is, does your compressor need new compressor pump gaskets? Odds are pretty good that in the disassembly of the pump a gasket may have been damaged if your pump has them.

If you don’t use new gaskets when you reassemble the pump, it is quite likely that the compressor pump assembly will leak while in operation, and your air compressor will still not build pressure correctly.

Replace all compressor pump gaskets.

Since a valve plate was not easily available, forcing the custom manufacture of the valve plate, likely the gaskets for that same pump may not be available either.

If a gasket kit for your compressor cannot be found, here’s how to make your own compressor gaskets.

Reassemble the pump with new gaskets and your custom built reed valve plate, and your compressor and you are back in business.

FAQs (Frequently Asked Questions)

What is a reed valve air compressor?

Air compressor reed valves are thin steel flaps fastened to the compressor valve plate. They’re a type of check valve that restrict flow of air to a single direction. Reed valves are essential in allowing low pressure air to enter the cylinders in all reciprocating compressors, and then pressurized air out of the cylinder.

How do compressor reed valves work?

As the piston travels down the cylinder of reciprocating air compressors, the suction valve opens to allow air in. As the piston travels upward and reduces the volume of the cylinder, air is pressurized and the discharge valve is forced open to release the now pressurized air.

How do you know if your air compressor valve is bad?

A sign that you may have a bad air compressor reed valve is that your compressor runs but doesn’t build pressure past a certain point. If the reed valve is broken or bad then the air goes back through the intake and no pressure is built.

How do you change a reed valve on an air compressor?

To change your reed valve on your reciprocating air compressor please follow these steps:

  1. Turn Off Compressor

    Disconnect the air compressor and then remove the plastic cover over around the motor and compressor

  2. Remove Cylinder Head

    Unscrew the screws holding the head on top of the compressor cylinder and remove the head

  3. Check the Reed Valve

    Underneath the head is the pressure plate, or valve plate, inspect the reeds for damage like warping or breaking.

  4. Make Note of Set up

    Take note of how the pressure plate sets and the o-rings that seal around it

  5. Remove Old and Install New Reed Valve Plate

    Remove the reed valve plate and then install the replacement

Reader Comments and Responses

What material are air compressor reed valves?

Question:

I have 2 questions about an old Ingersoll Rand compressor. Apparently my compressor is obsolete and there are no parts available, so I need to make new reed flapper valves. My OEM valve is .010″ thick.

Older Ingersoll Rand valve plate

Question #1: What shim stock is better to use, 18-8 stainless or 1095 spring steel?

Question #1: Would .012″ or .015″ shim stock make the valve less likely to break again, or would the thicker material effect the fill timing/ability?

Thank you!

Response:
by: Doug in s.d.ca.

Good questions.

The spring steel would be my choice, as it’s meant to flex.

I also would use a thickness as small as possible, that can withstand the pressure/area of the valve, also because thinner is more flexible and therefore less likely to break, as long as it isn’t hitting something other than the valve opening.

Too thick or stiff material will certainly impact efficiency, as a smaller opening due to limited valve travel will limit air flow.

Some pumps have a limiter finger above the valve, I take it this one does not?

Good luck.


If you have any questions regarding how to make our own air compressor reed valve, please leave a comment below with a photo if applicable so that someone can help you!