SWEP B45

The B45 suits a large temperature change at moderate flow. A 525 x 243 mm plate feeding a 23.7 m3/h (104.35 GPM) port ceiling gives a lot of surface per unit of flow, and the three-pass option stretches the thermal length further.

It goes wrong on the opposite duty: high flow with a small temperature change, such as a condenser-water or free-cooling loop. There the ports limit the unit long before the surface does, and the symptom is a pressure drop the pump cannot meet. That duty belongs on one of the higher-flow frames sharing this footprint.

Do not rely on draining. A multi-pass pack turns the fluid around inside the unit, and those turnarounds hold water that an open drain valve never reaches. With 0.241 dm3 in each channel there is plenty left behind to freeze and split the plates.

For any B45 that can see freezing conditions while idle, either keep it on a glycol mixture rated for the lowest ambient, or blow the circuits out with air after draining. Glycol raises viscosity, so pressure drop climbs and capacity falls - give the concentration when the unit is selected. See Glycol and Fluid Properties.

SWEP publishes the B45 at 0.427 kg per plate (0.941 lb per plate) with no separate fixed term, so the arithmetic is simple: 100 plates is about 42.7 kg (94.1 lb) and the full 251-plate pack about 107.2 kg (236.2 lb), dry.

At the upper end that is past what a wall bracket and two people should handle. Use a floor stand under the pack and never lift by the connections.

Treated water, glycol mixtures, oils and the common refrigerants are the normal range for this combination, and it covers most process heating and heat recovery work.

Three fluids rule it out. Ammonia attacks the copper braze. Deionized or ultrapure water leaches copper out of the joints and carries it downstream. Chloride-bearing water - pool, brackish, seawater or heavily chlorinated cooling water - pits 316 plate. The first two need a copper-free construction and the third needs SMO 254 plates. Temperature matters too: copper braze tops out at roughly 185 C. Plate and Brazing Materials sets out the options.

They share the 525 x 243 mm plate outline, 316 stainless plates and copper braze, and that is as far as the published match goes. The B50 is described for industrial duty where high power is needed, including steam-to-water and oil-to-water service.

Treat a B50 as its own model. The outline matching does not establish that the port centres, pass arrangement or connections do, and a steam or oil duty is selected differently from the water duties a B45 usually sees. Send us the full B50 designation and the duty, and we will confirm what replaces it.

By circulating a cleaning solution through it in place. Run it through the fouled side in reverse to normal flow, from a separate pump and tank, then flush until neutral.

On a three-pass B45, allow more time and check the flow rate of the cleaning pump. The fluid path is long and the pack holds a good deal of liquid, so a small pump produces too little velocity to lift deposits out of the far passes. The solution must also be compatible with copper braze.

These models are catalogued alongside the B45. Each has its own page with its dimensions, materials and part numbers.

SWEP B50 - Copper-brazed 316 stainless plate heat exchanger for high-capacity industrial duty, 525 x 243 mm.