SWEP P250AS

Yes. Circulate a cleaning solution through the water side against the normal flow direction, then flush and neutralize. Nothing else is possible on a brazed pack.

The cleaner must suit 304 stainless and copper. That rules out strong mineral acids and anything carrying chlorides, which 304 tolerates poorly. Milder acid cleaners made for brazed exchangers remove scale without harming the braze. Asymmetric channels do not change the method, but pay attention to which side is fouled: on a chiller it is nearly always the water side, and the trend to watch is water-side pressure drop at a known flow. A strainer ahead of the unit, sized for the published 0.8 mm maximum particle, prevents most of what cleaning has to fix.

For clean, treated, closed-loop chilled water and glycol, yes. That is what 304 with copper braze - material code NC - is intended for: ordinary water at lower cost.

It is the least tolerant of the stainless options. Chlorides, whether from poor make-up water, an open tower loop or a coastal site, will pit 304 before they trouble 316. Ammonia and deionized water are excluded by the copper braze. If the loop water is uncertain, tell us what it is; the F250AS on the same outline uses 316 channel plates, and we will confirm whether it is the better match. Plate and Brazing Materials compares the grades.

Because the two sides of an AsyMatrix plate are not the same size. The published channel volume is 0.172 on one side and 0.202 on the other, where a conventional symmetric plate would show one figure twice.

The practical consequences are refrigerant charge and response. The refrigerant-side volume multiplied by the number of refrigerant channels is the evaporator's contribution to system charge - a real constraint with charge-limited refrigerants, and one that grows with plate count. A small hold-up also means the evaporator reacts quickly to expansion valve and load changes. In reversible operation that helps the changeover, but it leaves no buffer against a loss of water flow.

The published approvals are PED, UL and KHK. For a chiller built and sold as a packaged machine, those are the approvals the manufacturer designed around, and a like-for-like replacement keeps the machine as it was approved.

Where it gets less simple is a field-built system or a jurisdiction that inspects pressure vessels individually. If the authority asks for an ASME stamp or a Canadian registration number, that needs to be raised before the order, not after delivery. Give us the requirement and the location and we will confirm what the unit can be supplied with.

Plates vertical, on its stand, with refrigerant and water in counter-current in the mode that matters most for efficiency. A reversible machine cannot be counter-current in both modes, since the refrigerant direction reverses and the water does not; the manufacturer's piping favors one.

So copy the original piping exactly. With asymmetric channels there is a second reason: each fluid belongs on its own side of the plate, and swapping them is not equivalent. Keep reversing-valve shock and compressor pulsation off the connections with proper pipe supports and vibration isolation. See Mounting and Piping.

SWEP's formula is 8.40 kg plus 0.3495 kg per plate (18.52 lb plus 0.771 lb per plate). That puts a 50-plate unit at about 26 kg (57 lb) and a 220-plate unit at about 85 kg (188 lb), dry.

Add the water and refrigerant it holds and the insulation, and the larger builds are well beyond what pipework should carry. Mount the unit on a base or bracket that supports the plate pack from below or clamps the covers.

These models are catalogued alongside the P250AS. Each has its own page with its dimensions, materials and part numbers.

SWEP B250AS - AsyMatrix in the H pressure class - 45 bar at 155 C.

SWEP F250AS - A copper-brazed single-circuit AsyMatrix evaporator for reversible chillers.