1. Need for an Insulation
2. Insulation Material
· Low temperature insulation:- Made of expanded cellular plastic or foam rubber material.
· Moderate temperature insulations: - Made from grass fibre products.
· High temperature insulation: - Made of preformed cementations or refractory materials or blankets made from ceramic fibers.
· Insulation and accessory materials have to be 100% asbestos free.
· Normally mineral fibre, cellular glass, ceramic fibre, glass fibre, polyisocyanurate, polyurethane foam etc are used as insulation material.
2. Few important points related to insulation
i. Hot insulation or Heat conservation insulation is used when normal operating temperature exceeds 65°C unless heat loss is desirable. (Control process temperature)
ii. Personnel protection is used in accessible areas if temperature exceeds 65°C.
iii. Steam traced, electric traced, jacketing etc are used for process temperature control.
iv. Insulation thickness is determined based on pipe size, normal operating temperature, temperature controlling requirement (extent of heat loss/gain) etc. At a minimum 25 mm thickness is used.
v. If insulation thickness is more than 75 mm then insulation is provided in two or more layers (multi layer).
vi. Insulation shall not be applied until hydrostatic/ pneumatic testing.
vii. Insulation upto 12 inch NPS pipe shall be held with ss 304 tie wire and for >12 inch NPS ss 304 bands are used.
viii. All flanges will be insulated other than hydrogen service or high health hazard material services.
ix. All valves other than control valves and relief valves shall be insulated.