Parker Prep-Air II 11F Compact Coalescing Air Filter, 1/4 in. and 1/2 in. NPT

Grade 6 coalescing elements, rated to 0.01 micron, for taking oil aerosol and fine water mist out of the air going to a paint gun, an instrument, a lab bench or anything pneumatic that resents oil.

Sizes

• 1/4 in. NPT, 45 SCFM (S1453, Parker 11F14EC)
• 1/2 in. NPT, 65 SCFM (S1455, Parker 11F34EC)

Specifications

• Grade 6 coalescing element, 0.01 micron
• Maximum inlet pressure 250 PSIG without the differential indicator, 150 PSIG with it
• Operating temperature 32 to 175 degrees F with a metal bowl, 32 to 125 degrees F with the indicator fitted
• Metal bowl with sight gauge, 4.4 ounce capacity
• Manual twist drain
• Pop-up differential pressure indicator

The older Watts Fluidair numbers for these two are F701-024E and F701-044E. Same parts.

Put a particulate filter in front of it

Parker says this plainly in their own literature and it is worth repeating because ignoring it is expensive. A coalescing element is a fine depth media. Hand it bulk water, rust and pipe scale and it blinds, the pressure drop climbs, and you replace a costly element months early. Fit a 40 micron particulate filter upstream, such as the 06F in the same body size, and the coalescer will do what it is rated to do for as long as it should.

Reading the pop-up indicator

The clear dome on top is a differential pressure indicator and it is the only honest way to know when the element is done. Coalescing elements do not look dirty when they are finished; they look fine and quietly cost you 10 PSI. When the button has risen, change the element, regardless of how long it has been in. Note the trade-off: fitting the indicator drops the maximum working pressure to 150 PSIG and the temperature ceiling to 125 degrees F, so on a 175 PSI system you want the version without it and a gauge either side instead.

Draining

A coalescer collects liquid oil, not just water, and that sump will not evaporate. The twist drain is manual, so it needs a person or it needs replacing with an automatic. Whatever comes out is oily water and in most jurisdictions it is not something you pour down a drain.