Insulations for process piping
Insulations are installed for the very obvious:
1) Heat conservation for economic purposes
-These are such as, preserving heat within a hot steam pipe during transfer from a boiler to the steam appliance
-or preserving cold coolant during transfer from air con condenser to the room evaporating unit.
-These are such as, preserving heat within a hot steam pipe during transfer from a boiler to the steam appliance
-or preserving cold coolant during transfer from air con condenser to the room evaporating unit.
2) Personnel protection purposes
- These insulation are usually thinner, to prevent direct contact between man and hot surface
- Insulation material can be replaced with a suitable cage, if heat needs to be dissipated for some reasons, or corrosion under insulation(CUI) is prevalent on the piping circuit.
- These insulation are usually thinner, to prevent direct contact between man and hot surface
- Insulation material can be replaced with a suitable cage, if heat needs to be dissipated for some reasons, or corrosion under insulation(CUI) is prevalent on the piping circuit.
3) Types of insulation
Mineral wool/Rock wool
This material is commonly used for hot service.
Operating range: 0 to 250(glass)/760(stone)/1200°C(ceramic)
It is usually white/yellow and sold in rolled bundles of wool. The process fluid used with this is usually non flammable, as mineral wool can induce fire, despite it being "fire resistant". Mineral wool can catalyse oil, breaking down it down to lighter and easily combustible components which makes it more dangerous. Note that it also absorbs moisture easily. Always wear gloves when handling, it irritates and makes the skin itchy.
Mineral wool/Rock wool
This material is commonly used for hot service.
Operating range: 0 to 250(glass)/760(stone)/1200°C(ceramic)
It is usually white/yellow and sold in rolled bundles of wool. The process fluid used with this is usually non flammable, as mineral wool can induce fire, despite it being "fire resistant". Mineral wool can catalyse oil, breaking down it down to lighter and easily combustible components which makes it more dangerous. Note that it also absorbs moisture easily. Always wear gloves when handling, it irritates and makes the skin itchy.
Calcium silicate
This material is usually used for hot service.
Operating range: -18 to 650°C
It is usually whitish, pre fabricated in blocks and appears like chalk. Good for use with hot oil service, as it does not catalyse oil. Also commonly used for fire insulation, see photo below for an example of a ductwork requiring fire protection rating.
This material is usually used for hot service.
Operating range: -18 to 650°C
It is usually whitish, pre fabricated in blocks and appears like chalk. Good for use with hot oil service, as it does not catalyse oil. Also commonly used for fire insulation, see photo below for an example of a ductwork requiring fire protection rating.
Foam glass
This material is commonly used for cold or hot service.
Operating range: -260 to 480°C
It is usually black color, pre fabricated in blocks, has the texture and characteristic of somewhat a harder styrofoam and can be cut to fit.
This material is commonly used for cold or hot service.
Operating range: -260 to 480°C
It is usually black color, pre fabricated in blocks, has the texture and characteristic of somewhat a harder styrofoam and can be cut to fit.
Polyurethane
This material is usually used for cold service.
Operating range: -210 to 120°C
It is usually yellow or white color, requires injection of PU foam into preinstalled cladding put in place around the piping/equipment.
Source: Wikipedia
This material is usually used for cold service.
Operating range: -210 to 120°C
It is usually yellow or white color, requires injection of PU foam into preinstalled cladding put in place around the piping/equipment.
Perlite
This material is usually used for cold cryogenic service.
Comes in sacks of white loose powder or compressed blocks. Very good for cold service, however needs to be kept dry for optimum performance. Usually used in N2 purged spaces or vacuum spaces.
This material is usually used for cold cryogenic service.
Comes in sacks of white loose powder or compressed blocks. Very good for cold service, however needs to be kept dry for optimum performance. Usually used in N2 purged spaces or vacuum spaces.
Vacuum jacketed insulation
This is usually used for cold service in cryogenic applications or hot service in thermoflasks.
It is very good method for preserving energy and vacuum level needs to be checked on intervals, if lost, needs to be replenished by hooking up a vacuum pump to "pull vacuum". Tell tale signs of losing vacuum are sweating on the exterior of vessel or algae formation.
Source: technifab.com
Installation of Insulation
The sizing of thickness and materials are very much dependent on application, process fluid and heat transfer rates to achieve less than 50°C on the external cladding surface for personnel safety reasons, as 50°C is usually the rule of thumb "ouch" threshold for humans.
During actual installation, we have no time to calculate the above, therefore tables are usually prepared before hand by the engineers, to advise the right insulation material and thickness. These information can usually be found on the piping specification which will specify different thickness for each application and the different temperature ranges.
eg. on the P&ID, isometic dwg or line list, the insulation fitter will have to interpret the following:
2"-HOTOIL-2330-1DC1A-1P ----> 1P usually refers to 1" of personel protection insulation.
2"-HOTOIL-2331-1DC1A-2H ----> 2P usually refers to 2" of heat conservation insulation.
Maintenance of Insulation
Insulation material when installed bare will disintegrate when exposed to effects of the environment, as such they are usually protected by cladding of aluminium or stainless steel material.
A sealant is then applied to the gaps where the cladding overlay each other.
Perlite insulation is different, it is usually dumped between the double skin section of the vacuum jacketed piping or vessel, as such it is easier to maintain.
Source: Wikipedia
1) Avoid stepping on insulation cladding during maintenance work
2) Check yearly to ensure sealant between cladding are in place
3) Install inspection ports for checking corrosion and thickness monitoring on the pipelines/vessels, these pockets will also be good for inspection the insulation condition beneath the cladding
4) Top up insulation material when they deplete under environmental deterioration
5) Avoid re-routing insulated piping to where they will be exposed to moisture, vents, drains and process mists areas
This is usually used for cold service in cryogenic applications or hot service in thermoflasks.
It is very good method for preserving energy and vacuum level needs to be checked on intervals, if lost, needs to be replenished by hooking up a vacuum pump to "pull vacuum". Tell tale signs of losing vacuum are sweating on the exterior of vessel or algae formation.
Installation of Insulation
The sizing of thickness and materials are very much dependent on application, process fluid and heat transfer rates to achieve less than 50°C on the external cladding surface for personnel safety reasons, as 50°C is usually the rule of thumb "ouch" threshold for humans.
During actual installation, we have no time to calculate the above, therefore tables are usually prepared before hand by the engineers, to advise the right insulation material and thickness. These information can usually be found on the piping specification which will specify different thickness for each application and the different temperature ranges.
eg. on the P&ID, isometic dwg or line list, the insulation fitter will have to interpret the following:
2"-HOTOIL-2330-1DC1A-1P ----> 1P usually refers to 1" of personel protection insulation.
2"-HOTOIL-2331-1DC1A-2H ----> 2P usually refers to 2" of heat conservation insulation.
Maintenance of Insulation
Insulation material when installed bare will disintegrate when exposed to effects of the environment, as such they are usually protected by cladding of aluminium or stainless steel material.
A sealant is then applied to the gaps where the cladding overlay each other.
Perlite insulation is different, it is usually dumped between the double skin section of the vacuum jacketed piping or vessel, as such it is easier to maintain.
1) Avoid stepping on insulation cladding during maintenance work
2) Check yearly to ensure sealant between cladding are in place
3) Install inspection ports for checking corrosion and thickness monitoring on the pipelines/vessels, these pockets will also be good for inspection the insulation condition beneath the cladding
4) Top up insulation material when they deplete under environmental deterioration
5) Avoid re-routing insulated piping to where they will be exposed to moisture, vents, drains and process mists areas
