SWEP B633

In place, by circulating cleaning solution through one side at a time. On a frame of this size the practical issue is flow rate: a small pump cart moves too little liquid to reach useful velocity across a wide pack, so the solution drifts through the easiest channels. Plan for a circulation pump and tank sized to the unit, and for flanged cleaning tees inboard of the isolation valves.

Clean on a trend, not on a failure. Log pressure drop and approach from commissioning and act when they drift, because a brazed unit left until it is badly scaled may not come back. The chemistry has to suit copper braze as well as 316 plate.

B633 is the frame, the 830 x 537 mm plate. L+M says the pack is built from two plate types together - L, the acute chevron with low heat transfer and low pressure drop, and M, the intermediate pattern. /1P is single pass on both sides. SC is 316/316L stainless plates with copper braze.

Y is the pressure class letter. It is not one of the classes with a published category figure, so take the design pressure and temperature from the stamped data on the unit, not from the letter.

A plate count, written as x and a number, and the connection description complete a real string. The strings on file, such as B633x130, show only frame and count.

It scales surface and paralell channels together: lower pressure drop at the same flow and a closer approach. The builds on file run from 50 to 220 plates, and the frame allows 348.

A 50-plate B633 suits a very high flow against a small temperature change. If the duty needs flow near the 349.9 m3/h ceiling and a close approach as well, the plate count has to rise with it.

Start with what cannot wear off. The 830 x 537 mm plate and 593 x 300 mm port centres identify the frame. Count the plates along the edge of the pack. Record the flange size and standard at each port and which ports are piped.

Two things cannot be recovered by measuring: the L and M plate mix, and the pressure rating. For those, any surviving fragment of the designation or the article number helps, as do the original plant documents or commissioning data. Send us photographs of the label and the unit with the operating duty, and we will confirm the build against it before a quote is issued.

Yes, and the size of the system makes it more necessary. The 1.1 mm limit describes the channel, which is no wider on a large frame than on a small one. A big network simply carries more debris to it: weld slag and scale from long pipe runs, and on open cooling circuits, organic matter and silt.

Size the strainer for the full flow at a low pressure loss, and make it cleanable without shutting the plant down - a duplex or automatic backflushing strainer earns its place where the circuit cannot be stopped. A blocked strainer starving the unit of flow is a nuisance. Debris inside a brazed pack is permanent.

The water, the pipework reactions and access. SWEP's formula, 40.71 kg plus 1.224 kg per plate (89.75 lb plus 2.698 lb per plate), is for the empty unit. A 220-plate build is about 310 kg (683 lb) dry, and each channel then holds 0.93 dm3 of fluid, so the operating weight is noticeably higher.

Carry the unit on its base on a frame designed for that load, and support the flanged headers independently so that neither their weight nor their thermal growth is taken through the connections. Leave room to reach all the flange bolts and the cleaning connections, and keep a lifting route open for the day the unit is changed.

The risk is at the plate surface, not in the bulk water. If the cold-side fluid entering is below freezing and the water-side flow slows or stops, the water in the channels can freeze even though the loop temperature reads safe. A frozen channel can split the pack.

Glycol on the exposed circuit removes the risk but costs capacity: the mix is more viscous and carries less heat, so pressure drop rises and the approach widens. A unit selected on water and later filled with glycol will fall short. Decide the concentration first and select on it, and interlock the cold side to proven water flow. Glycol and Fluid Properties covers the derate.