Old Curtis Compressor - Plunger Question

[ArXane]

What is the purpose of of the plunger/piston on the top of the head? As you can see from the picture it is bent and not functioning. With this removed, compressor builds pressure without an issue. I assume this is a for a blow off or bypass of some kind? I have read its for easier starting of the compressor?

Is there anything updated/electronic I can swap it with?

Thanks.

 

[vonhef]

What is the purpose of of the plunger/piston on the top of the head? As you can see from the picture it is bent and not functioning. With this removed, compressor builds pressure without an issue. I assume this is a for a blow off or bypass of some kind? I have read its for easier starting of the compressor?

Is there anything updated/electronic I can swap it with?

Thanks.

It is a mechanical unloader valve. This allows the compressor to start without compression, then as the centrifugal weights move when the flywheel spins, it will move the arm and close the unloader valve to allow compression.
Some of the newer compressors may have electric controlled unloaders??

 

[vonhef]

I have an old Curtis, and the mechanical arm was worn were it rides against the flywheel:

I repaired it and reinstalled:

Now it works great:

 

[ArXane]

I have an old Curtis, and the mechanical arm was worn were it rides against the flywheel:

I wish mine was just wore out like that. My piston/plunger is actually bent and and not working. The insides of it have a bunch of lead/rock like stuff in it that just fell apart when I took it apart. Ill see if I can find some type of electronic unloader and remove all the mechanical part of the unloader I guess.

Thanks.

 

[Milton Shaw]

If you have a check valve between the compressor and the tank and then a pressure switch that is piped into that output line and has a built in unloader you should be good to go.. That motor looks like it should be heavy enough to start that compressor it if does not have air pressure from the tank as a load at starting. That compressor may have been originally a gasoline engine unit that would need a compressor unloader. Most electric motors have enough power to start with start coils and capacitors.

 

[ArXane]

If you have a check valve between the compressor and the tank and then a pressure switch that is piped into that output line and has a built in unloader you should be good to go.. That motor looks like it should be heavy enough to start that compressor it if does not have air pressure from the tank as a load at starting. That compressor may have been originally a gasoline engine unit that would need a compressor unloader. Most electric motors have enough power to start with start coils and capacitors.

Good to know, It doesnt seem like it has a hard time starting. It does NOT have an unloader between the two, ill be sure to put one in. Thanks Milton

 

[Ddog]

It is a mechanical unloader valve. This allows the compressor to start without compression, then as the centrifugal weights move when the flywheel spins, it will move the arm and close the unloader valve to allow compression.
Some of the newer compressors may have electric controlled unloaders??

 

[Ddog]

Could you be more specific or better pitchers of what you're actually talking about please thank you

 

[Ddog]

Could you be more specific or better pitchers of what you're actually talking about please thank you

Or maybe pitchers of the arm that closes the uploader so for compression that has to be my problem mine want build up comprehension thank you

Could you be more specific or better pitchers of what you're actually talking about please thank you

 

[Ddog]

Or maybe pitchers of the arm that closes the uploader so for compression that has to be my problem mine want build up comprehension thank you

Or maybe pitchers of the arm that closes the uploader so for compression that has to be my problem mine want build up comprehension thank you

I've got to Get er done I just got to

 

[BillK]

Ddog,
This thread is from 9 years ago. Hopefully he has fixed it by now

 

[Ddog]

Ddog,
This thread is from 9 years ago. Hopefully he has fixed it by now

I just received it from my dad and moving it from his place to my place I must have lost the part that works the uploader I would just like to see a picture of it so I know what it looks like or video of it in operation would be great or both would be even better easy pleasy

 

[BillK]

I just received it from my dad and moving it from his place to my place I must have lost the part that works the uploader I would just like to see a picture of it so I know what it looks like or video of it in operation would be great or both would be even better easy pleasy

Is yours the same as the one in this thread ? I have an ancient Curtis Compressor and have e-mailed Curtis a few times and they will send you parts diagrams. https://us.fscurtis.com/

WHat model number is your compressor ? Is the unloader operated by weights on the flywheel ?