Current options for moderate duty scuba compressor?

[PBcatfish]

The link for the Davy (Dav v?) compressor didn't work for me. I googled around & found some information on them. The most telling was this video from a trade show - . It looks to me like they take products from many sources & brand label them. The one unit looks like a Coltri. Another looks like a Yong Heng with a cheap re-loadable filter cartridge of the type that is available to paintball guys. They also had what looks like a booster that I did not recognize, but would like to learn more about. It may not be a booster. It may be a 2-head diaphragm compressor to be used as a hooka. I did not find data on it. They had others that I did not recognize.

I also found this website, which uses the name Davy & claims to be a USA site, but seems to also brand label scuba compressors from other places. - Scuba Breath High Pressure Air Compressor 6cfm 4500psi for Filling – Davyenergy

I have seen advertisements for the chinese knockoff compressors on ali before. I too am curious about the quality.

 

[iain/hsm]

The alkin is rated for continuous run, the coltri is not.

Neither is the Alkin it is not even close to a continuous rated compressor.
Maybe Alkin don't fully understand the term continuous rated or those poor sports divers
that make up the customer base and buy the thing don't care and are happy to believe a lie.

 

[formernuke]

According to Alkin it is rated for continuous run

 

[grf88]

many bauer compressor on ebay from india... look very suspect

Probably coming from the ship wrecking yards.

 

[Gone for diving]

Neither is the Alkin it is not even close to a continuous rated compressor.
Maybe Alkin don't fully understand the term continuous rated or those poor sports divers
that make up the customer base and buy the thing don't care and are happy to believe a lie.

So then a dumb question...
What makes it not, continuous rated.
( Beside getting to hot).

Or maybe a better way of putting it,
What makes a compressor continuously rated?

 

[tbone1004]

So then a dumb question...
What makes it not, continuous rated.
( Beside getting to hot).

Or maybe a better way of putting it,
What makes a compressor continuously rated?

to be continuous rated the cooling capacity needs to meet or exceed the heat being generated. Essentially the unit hits a temperature and stays there, much like your cars engine does. Once it hits that temperature it can run forever without getting any hotter. These units are likely suffering from a lack of cooling capacity *small oil sumps, no oil coolers, inadequate fans, inadequate cooling tubes, etc* and if you run them for more than 15-20 minutes then it's heat soaked and is generating more heat than it can shed which is obviously bad.

 

[Gone for diving]

to be continuous rated the cooling capacity needs to meet or exceed the heat being generated. Essentially the unit hits a temperature and stays there, much like your cars engine does. Once it hits that temperature it can run forever without getting any hotter. These units are likely suffering from a lack of cooling capacity *small oil sumps, no oil coolers, inadequate fans, inadequate cooling tubes, etc* and if you run them for more than 15-20 minutes then it's heat soaked and is generating more heat than it can shed which is obviously bad.

I agree that heat is very bad, and probably is the limiting factor,
An I am very disappointed with how badly most compressors cooling fan work.

So a fairly simple fix is to give these small compressors an external fan to help with cooling,
Like a 110v blower fan or like an electric radiator fan,

 

[PBcatfish]

I have noticed that most continuous duty units have forced lubrication & most that are not full duty do not.

The fan on the Bauer Utilus 10 I have been messing with, blows quite hard across the pump & the coils. Adding an external fan would not increase air flow in those areas.

An external fan that brought cooler air into a warm compartment that housed the compressor would be an improvement.

 

[rob.mwpropane]

I have noticed that most continuous duty units have forced lubrication & most that are not full duty do not.

The fan on the Bauer Utilus I have been messing with, blows quite hard across the pump & the coils. Adding an external fan would not increase air flow in those areas.

An external fan that brought cooler air into a warm compartment that housed the compressor would be an improvement.

I guess what you mean by forced lubrication is oil cooled?

My Rix (~5cfm) does not use oil for the pump. It's air cooled, continuous duty to 3600psi. The fan on the front kind of sucks, so I add an additional shop fan in front to aid in cooling when running.

 

[PBcatfish]

I guess what you mean by forced lubrication is oil cooled?

My Rix (~5cfm) does not use oil for the pump. It's air cooled, continuous duty to 3600psi. The fan on the front kind of sucks, so I add an additional shop fan in front to aid in cooling when running.

I was referring to an oil pump that forces oil into the cylinders, as opposed to splash lubrication, where the crank pin hitting the oil bath causes splashes of oil to reach the cylinders. It is my understanding that little Bauers like the Jr & it's predecessor the U10 had only splash lubrication, while larger constant duty units like the Capitano, Utilus, Oceanis, and commercial units had lube pumps with regulators.