Specifications

LWLCWH COLUMBIA BOILER COMPANY REV. 13106

Safety Valve / Relief Valve

All safety or relief valves are located in the rear center fitting on top of the boiler. A 15 PSI Steam

Safety Valve is supplied for steam boiler and water heater applications. A 30 PSI Water Relief Valve is

used for hot water applications. All safety and relief valves should be safely piped away from the boil-

er without reducing the valve s outlet port size.

Steam Supply

Pipe the steam lines to the largest fitting or flange located on top of the boiler.

Note: For CWH UNITS ONLY - Plug the main steam outlet unless an expansion tank is used.

Hot Water Supply

Use the fitting/pipe flange on the top of the boiler for the hot water supply to the system. Hot water

applications also require the use of an expansion tank in the supply piping, to compensate for fluctu-

ations in the water volume during heating and cooling cycles.

Feed Water Supply

Virtually any unused port on the heat exchanger can be used for the feed water supply, including any

unused drain port. In situations where make up water is needed, the water supply must be treated

before it enters the boiler, to prevent the formation of scale, or to protect the boiler surfaces from the

corrosive effects of oxygenated water. Water treatment and a water treatment program must be prac-

ticed, or the life of the boiler will be severely limited. If a Condensate Return / Feedwater Tank is used,

connect the feedwater source to the float valve on the tank.

Coils

Boilers are shipped with the coil(s) assembled to the coil plate(s), and mounted in the boiler. For the

smaller L-Series, L-18(CWH-170) thru L-24(CWH-390), the coil plates cover the opening for which the

coils pass through. The indirect water inlet and outlet connections are made in the rear of the boiler.

All other Columbia models can be furnished with one or two coils. CWH models larger than a CWH-

390 always have two coils.

When making coil connections for twin coil units, manifold indirect water piping using copper tubing

and fittings connected in parallel. Pipe the outside coil openings together for cold water inlets, and

the inside coil openings for hot water outlets. If necessary, temper the hot water supply by using a

mixing valve. Connect the hot water outlet source and a cold water supply line to a mixing valve, to

temper the hot water supply to the proper temperature requirements for process equipment.

Whenever boilers are supplied with one or two coils, the coils must be covered by a minimum of two

inches of water, during normal operation, to allow proper heat transfer through the coil. Adjust all

LWCO piping to keep the coil(s) submerged in the event of a low water situation.