INSULTECH

Low Temperature STEAM Below 450ºF - Wet Manholes and Confined Space

Application: Wet Manholes & Confined Space
• Gate Valves • Slip Expansion Joints • Flanges • Piping • Bellows Expansion Joints • Ball Joints • Flanged Fittings

Market
• Utility Steam Distribution • Institutional Steam Distribution

Design Components:

Blanket Thickness Surface Temperature Reference:

Thickness/Surface Temperature

• The above reference cold face surface temperatures should be used as guidelines for blanket thickness design.
• The cold face surface temperature of the blanket should achieve ambient temperature conditions.
• The economic thickness of the blanket should consider blanket cost to thermal performance.
• Heat loss calculations are based on a 70ºF ambient using a flat surface condition.

Fabrication Requirements

Blanket Construction
Blanket construction shall be a double sewn lock stitch with a minimum of 7 stitches per inch. All raw jacket edges will have a tri-fold Teflon Nomex cloth binding. No raw cut jacket edge will be exposed. Stitching will be done with all Teflon, 3 ply braided thread.

Blanket Overlap
Blanket will overlap mating flanges as well as existing insulation with a minimum of 3" overlap. Where blanket cannot overlap existing oversized insulation, blanket will butt up to existing insulation with a friction closing seam. Open gaps are not acceptable. Blanket diameters which are 2" larger than existing insulation must be end capped to eliminate open air void.

ID Plates
For easy identification and location, a stainless steel or aluminum name plate tag is riveted to each blanket piece. 1/8" Embossed lettering shows location, description, size, pressure rating and tag number sequence.

Leak Accommodations
To accommodate a leak and detect its origin, blankets will have a low point brass drain grommet or the design will incorporate a mating seam at the low point.

Blanket Insulation Weight
When designing blanket insulation for large equipment where a multi-piece construction is necessary, the total number of pieces will be minimized. Any one piece will not exceed 50 lbs. in weight. In addition, an installation assembly drawing will be included to identify blanket location.

Minimized Air Void
Blanket design will conform to equipment with minimized air void. Expansion joint blankets will have a separate body & slip blanket. The slips will have blanket collars to overlap existing insulation and to match the expansion joint body blanket.

Quilting Pins
To enhance blanket quality and maintain uniform thickness, stainless steel quilting pins will be placed at random locations no greater than 18" apart. This will prevent shifting of the insulation filler.

Standard Fastener
The blanket fastener will be 2" Polypropylene Side Release Buckles with 1.75" wide Fabric Straps. A tri folded 1.75" finished width belt will be sewn together using all Teflon, 3 ply braided thread. Two parallel rows of stitching will be placed on both sides of the belt full length. The Buckle strap will be a minimum of 7" long and will be box stitched to the outer jacket surface a minimum of 5". A matching pull strap will be sewn on the outer jacket surface and will match up to the Buckle strap. The pull strap will be a minimum 16" long.

Assembly Drawing Requirements
Each blanket insulation project will include an instruction package shipped with the blanket material. This package will include Assembly Drawings identifying piece location, a Material List of all pieces and Instructions for Installation on how blanket insulation will be installed. The latest and most accurate records must be kept by the supplier on a CAD file for a minimum of ten years to assure re-orders and replacement.

Project Qualifications
All items to be insulated will require a field takeoff prior to bid submittal, and must be reviewed for proper cost estimation. Upon receipt of project contract, each and every item must be accurately measured for retrofitting to existing field conditions and tagged with an aluminum or stainless steel identification tag showing an item number for installation reference. At the time of installation, blankets must have a corresponding item number shown on the blanket tag and must match to existing tagging on fitting. No standard blanket designs will be accepted. This will assure good thermal performance.

Warranties
All blankets will carry an 18 month warranty covering the replacement cost of the blanket. This warranty will cover blanket failure due to premature degradation from either blanket components used in the blanket, the blanket design construction or workmanship.

Design Construction Sample
Upon bid submittal a blanket design construction sample must be presented for review and product approval. A 2 piece 4" Gate Valve Sample will be required and must identify all characteristics mentioned in the above fabrication requirements. Any deviation from the above requirements may result in rejection.

Design Guidelines
To access the true limitations of this recommended design, refer to the technical data sheets on each product component. Following these guidelines will produce the highest achievable service life. Blanket design quality can be reduced or enhanced by changing any one component. If a question arises regarding deviations from those stated guidelines, please contact your regional representative or call Shannon direct.