SWEP F85AS

SWEP publishes threaded, solder and combo connections. There are no catalogued F85AS part numbers on file, so the connection at each port is chosen with the order, typically solder on the refrigerant ports and threaded or combo on the water ports.

A combo connection, written with an ampersand in the designation, accepts two joining methods or sizes at one port. A solder size ending in U is universal and takes both imperial and metric tube - 28U fits 1 1/8 in and 28.75 mm, and 22U covers 7/8 in and 22 mm. Connections are listed in port order at the end of the designation, so copy that string exactly from the old unit.

Rarely on this model. SWEP's example designation is single-pass, F85ASH/1P-NSC-MY, and that is the natural arrangement for an evaporator with a distribution system at the refrigerant inlet: one inlet, one trip up the plates, one outlet.

Multi-pass arrangements earn their place on single-phase duties that need a long thermal path. They raise pressure drop and put connections on the rear cover. On an existing installation the pass code after the slash has to match, or neither the pipework nor the refrigerant feed will suit the new unit.

On the refrigerant side, the modern high-pressure refrigerants it was designed around. On the other side, water or a water-glycol mix. The construction is 316 channel plates with 304 cover plates and copper braze, coded NSC.

It does not suit ammonia, which attacks copper braze, or deionized water, which leaches copper; both call for a copper-free construction. Chloride-bearing water pits 316 and is an SMO 254 duty. Name the refrigerant when asking for a quote, because the pressure class follows from it. Refrigerant Compatibility has more.

No. The published maximum flow of 17 m3/h (74.85 GPM) is a ceiling set by the ports. A design flow sits well under it, at a point where pressure drop through the ports and channels is acceptable to the pump.

If the required water flow approaches the ceiling, adding plates does not help - plates reduce channel pressure drop, not port velocity. The B85, B85S and F85 share the same 74.85 GPM limit, so moving sideways in the family gains nothing either. The answer is a frame from the 75 to 200 GPM band.

All four have a 74.85 GPM maximum flow. The F85AS and F85 are 524 x 117 mm; the B85 and B85S are 526 x 119 mm.

The F85 is the condenser and demanding-duty unit on the platform. The F85AS takes that platform and adds AsyMatrix channels and an integrated distribution system, making it the evaporator, usable as a reversible condenser. The B85 is the 316/316L copper-brazed unit on the larger outline. The B85S is the All-Stainless model - 316 plates with stainless braze - for systems that need fully stainless components or high temperature.

Pick by duty and metallurgy, then confirm the outline.

SWEP publishes a 0.8 mm maximum particle size, so the water-side strainer has to stop anything larger.

The strainer matters more on an evaporator than on most duties. Solids collect at the channel entrances, the affected channels carry less water, and that water is chilled further than the rest. The result is local freezing inside a unit whose leaving water temperature still looks normal on the gauge. Fit the strainer close to the water inlet, and treat a rising water pressure drop as a prompt to clean it and to check the unit for fouling.

Keep water moving and keep the evaporating temperature above the freezing point of the fluid. In practice that means proving flow before the compressor starts, holding it through pump-down, and using glycol wherever the leaving temperature or the ambient makes freezing possible. Ice in the channels can split a brazed unit, and it cannot be repaired.

Glycol changes the rating. It is more viscous than water, so pressure drop rises and heat transfer falls, and the plate count chosen on water may be short on a glycol mix. Give the glycol type and concentration with the duty. See Freeze Protection.

These models are catalogued alongside the F85AS. Each has its own page with its dimensions, materials and part numbers.

SWEP B85 - 160 plates on the 526 mm frame, with tighter channels than the B80.

SWEP B85S - An All-Stainless, high-efficiency brazed plate heat exchanger with large ports.

SWEP F85 - A compact copper-brazed plate heat exchanger with large ports for high-performance condensers.