Safety Head ?

[Gavin R96]

Hi

I am very new to re-frigeration and this may seem a very basic question but I was wondering if someone could explain Safety Head and state its function.

Thanks for any information

Gavin

[NH3LVR]

Welcome to tthe forum Gavin:)
Are you refering to the spring loaded discharge valves on compressors?

[ruvy frank]

we welcome you to the forum givvy. can you explain more as to what it is and where it is located.

[Chunk]

Welcome.

Safety head springs are provided between the valve plate and the cylinder head.when excessive pressure is developed in the cylinder,such as in the case of liquid flood back,the valve plate is lifted up against the spring pressure,thus preventing any damage to the compressor.

[Chunk]

Or a longer answer.

Liquid slugging can damage the compressor by washing oil out of crankcase or entering the cylinder.trying to compress liquid can blow the cylinder head.
To protect the compressor from liquid slugs certain systems have safety heads fiited.

The safety head has an internal discharge valve plate at the top of the cylinder directly in front of the discharge pipe.This discharge valve plate lifts,making the full opening of the discharge pipe accessible to the cylinder.

This moving valve plate will not open unless hydrostatic pressure builds up in the cylinder,it is held down by a heavy helical spring.

If liquid is trapped in the cylinder and the piston starts its compression stroke,the liquid will push solidly against the safety head.Since liquids do not compress,the safety head allows any liquid that enters the compressor to be expelled from the discharge,without physical damage to the compressor.As the piston starts to come back down,the helical spring forces the safety head back into position.

[Gavin R96]

Thanks very much for your responses, it is appreciated

[Brian_UK]

Gavin, if you have a look at the recip compressors on this website...
http://www.berg-group.com/Refrigeration_SystemComponent.htm
you will see the safety springs on the cylinder heads.