SECTION III: STEAM Boiler PIPING & TRIM
WARNING
Failure to properly pipe boiler may result in improper operation and damage to boiler or structure.
Do not increase steam boiler input above the ratings.
A.Evaluate the existing steam system.
The single most important factor in determining the expected life cycle of a steam boiler, is the amount of fresh water added to the boiler during operation. Fresh water brings minerals and oxygen into the boiler. These contaminants greatly accelerate corrosion of the cast iron boiler sections.
1.Assure that all system radiators, piping and vents are absolutely leak tight.
a.When a steam boiler is installed in an existing system, ALL air vents should be replaced at the same time. This assures that the new boiler will not be compromised by existing system leaks.
b.If the system contains hidden supply or return piping (hidden behind walls, buried in concrete, etc.) pressure test this piping to assure there are no leaks.
2.Repair any leaks in the system.
3.Install accurate water meter on the fresh water supply to the boiler.
B.Connect system supply and return piping to boiler. See Figure 11 for piping details. Also consult I=B=R Installation and Piping Guides.
CAUTION
Maintain minimum ½ inch clearance from hot water piping to combustible materials.
NOTICE
Do not use softened water in steam boilers. Accelerated boiler corrosion will result. Tie in fresh water supply to the boiler upstream of a water softener.
Oxygen contamination of boiler water will cause corrosion of iron and steel boiler components, and can lead to boiler failure. Burnham's Standard Warranty does not cover problems caused by oxygen contamination of boiler water or scale (lime)
Before using copper for steam piping, consider the following characteristics of copper piping:
1)high coefficient of thermal expansion can induce mechanical stresses and cause expansion/ contraction noises if not accounted for in the piping system design and installation,
2)high heat transfer rate (heat loss) of uninsulated copper piping must be included in the normal piping and pickup factors used to size the boiler,
3)soldering or brazing pastes and fluxes that end up in the system can cause poor heat transfer, surging, an unsteady water line and wet steam if not thoroughly removed during the boil out procedure and,
4)galvanic corrosion of the adjoining metal may occur due to dissimilar metals in certain water chemistries if dielectric unions are not used.
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