2021 Air Compressor Vote

Sponsor

David Earl

Co-Sponsors

Andrew Morris

Brian Desmond

Gary Newhouse

History

Announced: September 14, 2021
Language Locks: September 17, 2021
Vote: September 21, 2021

Background

The air compressor is a critical piece of operational infrastructure at Pumping Station. Numerous areas depend on compressed air for their tools to run correctly (or at all), including:

Hot metals: blast cabinet and plasma cutter
Lasers: all of them
Tormach milling machine
Spray booth
Cooling air at the shopbot

Our current compressor stage has suffered an intermittent mechanical or electrical failure that has proven difficult to diagnose, even by Zorn, the compressor company we called for help. Additionally, Zorn has had great difficulty sourcing replacement parts for our 45-year-old compressor, and Quincy, the manufacturer, has been non-responsive to our requests for service and parts.

The service technician noted numerous safety-related concerns about our compressor, including:

The cushion chamber is no longer legally able to be manufactured due to an explosion hazard; it was a common feature on older compressors.
The drive belt is beyond end-of-life.
There is no belt guard present.
The gaskets used to attach the compressor stage to the tank are improper.
The safety pressure release valve is not directly attached to the tank, reducing its effectiveness.

The compressor stage head gasket has a history of leaking badly due to over-torquing the head bolts, causing the head to warp. The compressor requires regular replenishment of oil, placing a timely and unnecessary burden on operations team members and increasing running costs.

Additionally, there are numerous comments of moist air arriving at tools because there is no refrigerator/drier unit to remove the water.

Another issue with the current setup is that the electrical panel breaker to which the compressor is attached is only rated for 30 amps when it should be 60 amps (the power disconnect switch for the compressor in the utility room is rated for 60 amps.) This breaker has been on the Gen Ops replacement list for some time, but will require shutting down power to the entire shop as the panel is the first off of the power transformers.

Zorn “absolutely recommend(s)” going with a traditional piston-style compressor for our use case and duty cycle. While rotary screw type compressors were discussed with Zorn, the unit they recommended retails for $8500 and physically does not fit in our utility room; this would necessitate restructuring a significant portion of our compressed air line infrastructure, as well as placing the compressor outside of the utility room losing valuable shop floor space. They also mentioned that, even if it did fit, the ambient temperature of our utility room would significantly shorten the service life of a rotary screw-type unit.

Our current compressor is set to produce ~35 CFM at 125 psi with a 120 gallon tank. The proposed new unit is rated for 40 CFM at 175 psi with a 120 gallon tank, but the unit comes with an adjustable pressure switch that should allow us to reduce the pressure to 125 psi consistent with the current setup. This will produce a higher CFM rate of flow at the same pressure, which is beneficial for high-volume tools such as the spray booth.

Have any particular machine in mind?

What about the old unit?

The old Quincy compressor will be disposed of per Asset Disposal policy: https://wiki.pumpingstationone.org/Asset_Removal_Policy

Vote Language

Authorize the BoD to spend up to $7000.00 on acquiring a new air compressor, compressed air dryer, and associated components. This authorization shall expire at midnight on December 31, 2021.

Voting

Quorum:

Present:

For:

Against:

Abstain: