INSULTECH

Mid Temperature STEAM 450ºF to 800ºF

Application
• Gate Valves • Single Stage Steam Turbines • Globe Valves • Small Multi-Stage Steam Turbines • Orifice Flanges • Expansion Joints • Feedwater Pumps • Pressure Reducing Valves

Market
District Heating Plants • Industrial Boiler Rooms • Utility Power Plants • Cogeneration Power Plants

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 single sewn lock stitch with a minimum of 7 stitches per inch. All raw jacket edges will have a folded Silicone Fiberglass cloth binding. No raw cut jacket edge will be exposed. Stitching will be done with a stainless steel thread. To enhance the sewn quality and to reinforce the finished fabric edge, Monel staples will be placed 1" on center along the binded edge.

Blanket Overlap
Blanket will overlap mating flanges as well as existing insulation with a minimum of 2" 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 capped to eliminate open air void.

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

ID Plate
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.

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.

Blanket Insulation Design
When designing blanket insulation for large equipment where a multi-piece construction is necessary, the total number of pieces is minimized. Any one piece will not exceed 50 lbs. in weight.

Minimized Air Void
Equipment and equipment heads are typically a multi piece design and are installed in tag number sequence. Heat exchanger heads, large vessel flanges and pump housings will be designed in two half sections. Blanket design will conform to the equipment with minimized air void.

Standard Fastener
Blanket insulation will accommodate any of the fastening options. A 20 gauge stainless steel wire will be doubled up and twisted in a spiral fashion with a minimum of 4 twists per inch. Wiretwist length will be 16" or greater. The Wiretwist will be secured to the lacing pin at the pin stem. Lacing pin stems will be 14 gauge. Lacing head will be a Type 93A, with a parallel hook and tapered throat.

Fastening Option

Stainless Steel "D" Ring Strap with Velcro Tab
A three layer fabric strap is double sewn. One strap is a 16" long pulldown strap, the other is a 6" long stationary strap. Both straps are stitched to the outer jacketing of the blanket. The stationary strap includes a 304 stainless steel "D" Ring measuring 1.125" to 1.25" in width. This is placed 1/2" from the closing seam edge. The pulldown strap is placed 3" in from the closing seam edge. Both matching straps are spaced along the closing seam edge no greater than 8" apart. The pulldown strap includes hook-and-loop velcro, measuring at least 1" wide by 6" long, and is perimeter stitched to the strap surface. All closing seams have a 1.5" extended fabric flap, which is placed along the stationary strap side of the closing seam.

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 deviations from the above stated 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.