Insulation of Vessels
2.2.1 Note to Specifications
Under the general heading 'insulation vessel' can be included small and large rectangular, cylindrical and irregular pieces of equipment, high towers for chemical process plants, large storage tanks and spheres as well as boilers and steam turbines. Because of the complexity of this equipment it is not possible to provide model specifications to meet all requirements. However, there are certain basic principles which must be observed, and the following will provide the necessary information to assist in drawing up detailed specifications for using Isover Stonewool products for the insulation of this type of equipment. In selecting the most suitable product the following criteria must be considered:
- Maximum service temperature
- Degree of insulation efficiency required
- Robustness of insulation necessary to support the applied finish and withstand the environment
- Thermal insulation of ducts, vessels, boilers, ovens and in dry wall applications
Generally the higher the temperature, the higher the density required. It may be prudent to select a density of slab higher than that which is necessary for the temperature, where more robust insulants is required to support the covering, and other loads, which may at times be imposed, e.g. foot traffic on top of large tanks.
Cylindrical Vessels Model Specifications
2.2.2. Application of Insulboard
Cylindrical vessels shall be insulated with Isover Insulboard in suitable thickness and density, firmly secured to the vessel with metal bands, adhesive or a combination of both. The metal bands should not be over-tensioned so as to significantly reduce the thickness of the insulation.
On vertical surfaces, circumferential support rings shall be fitted and spaced apart at distances which will provide adequate support according to the weight of the insulation. The support rings shall protrude from the vessel to a maximum distance of 10mm less than the thickness of the insulation. All joints must be well butted together and vertical joints on adjacent courses staggered. In multi-layer applications all joints shall be staggered.
The insulation may be fixed to domed ends by impaling over pins and securing with spring washers or forked pins welded to the vessel. In either case the outer end of the pins should be depressed below the surface of the insulation to prevent heat being transmitted direct to the covering.
2.2.3. Application of Insulmatt
Vessels to be insulated with Isover Insulmatt of suitable thickness and density. Metal pins or forked studs to be welded/screwed to the surface of the vessel at the following pitches: on vertical surfaces at an approximate square pitch of 450mm, upward facing surfaces 600mm, overhanging or downward facing surfaces 300mm. When using pins with spring clip washers, the length of the pin to be 12mm shorter than the thickness of the insulation to avoid hot spots on the cladding. Forked studs to be longer than the insulation thickness. The mattress to be impaled over the pins, secured with 50mm flat square washers and capped with spring clip washers. Forked studs should be turned back and recessed into the insulation by approximately 10mm. Mattresses to be closely butted together and the edges of the outer layer of wire netting laced together with wire. Joints of multi-layer insulation should be staggered.
Rectangular Vessels, Tanks, or Flat Surfaces
Any density of Insulboard can be used in such applications, actual choice depending on performance required.
2.2.4. Application of lnsulboard
To be insulated with Isover Insulboard of suitable thickness, secured to the surface to be insulated with suitable adhesive. The adhesive to be applied to cover the entire surface. (It is important to follow manufacturers’ instructions).
Alternatively the insulation may be impaled over pins fixed to the surface of the vessel at the following pitches: On vertical surfaces at an approximate square pitch of 450mm, on upward facing surfaces at approximately 600mm and overhanging or downward facing surfaces 300mm. Location of pins should be arranged so that there is a pin not more than 50mm from each corner of each slab.
All joints should be closely butted together. Vertical joints (and in multi-layer applications all joints) must be staggered, and at corners, adjacent slabs must be overlapped to the thickness of the insulation. When using pins with spring clip washers, the length of the pin should be 10mm less than the thickness of the insulation to avoid hot spots on the cladding.
2.2.5 Application of lnsulmatt
Vessel to be insulated with Isover Insulmatt of suitable thickness and density. Metal pins or forked studs to be welded/screwed to the surface of the vessel at the following pitches: On vertical surfaces at an approximate square pitch of 450mm, upward facing surfaces 600mm, overhanging or downward facing surfaces 300mm.
When using pins with spring clip washers the length of the pin should be 10mm less than the thickness of the insulation to avoid hot spots on the cladding. Forked studs to be longer than the insulation thickness. The mattresses to be impaled over the pins secured with 50mm flat square washers and capped with spring clip washers. Forked studs should be turned back and recessed into the insulation approximately 10mm.
2.2.6 Sheet Metal Cladding
The application of sheet metal cladding must meet certain requirements which are set out below, but a specific design may be necessary depending on size, location, environment, etc. Special types of studs which reduce heat conduction may have to be provided, welded to the vessels surface or other profile sheet may be used.
All circumferential joints must be overlapped in order to shed water, and secured with self-tapping screws or easy-fix rivets. Where necessary joints should be sealed with a suitable sealant to prevent the ingress of water or other contaminating fluids. On large vessels certain overlaps should be designed to provide for expansion.