Specifications

Modular or Multiple?

ASME Section IV differentiates between a modular and multiple boiler installation. According to ASME, a modular

boiler system consists of individual modules with a maximum input of 400 MBH each. Each module is to be

equipped with a pressure temperature gauge, temperature limit control, safety relief valve, and drain valve. The

modules are to be manifolded together on site without any intervening stop valves. The modular boiler assembly is

to be equipped with a common temperature limit control, low water cutoff, makeup water connection, provision

for thermal expansion, and supply and return stop valves.

Multiple boiler installations require a stop valve in the supply and return pipe connection of each boiler.

Each boiler needs to be equipped with a pressure temperature gauge, two temperature limit controls,

safety relief valve, and drain valve. Boilers over 400 MBH must also include a low water cutoff.

Sizes 805, 6, and 7 can be installed as modular or multiple boilers. Sizes 808, 9, and 10 are

to be installed as multiple boilers. In both cases, minimum recommended side-to-side

clearance is one inch or as required by local codes.

Enjoy the Peace of Mind That Comes

with Modular and Multiple Boilers