Hot Pipe Shoe Support Specifications

Scope

This specification covers the requirements for the design, fabrication and use of our pre-insulated low temperature pipe supports. These supports are for pipes having surface temperature ranges of 40°F (4.4°C) to 1800°F (982°C).

General Requirements

  • All insulated pipes shall be supported with pre-insulated pipe supports.
  • Pre-Insulated pipe supports shall comply with the following standards:
    • ANSI/ASME B31.1 & B31.3
    • Manufacturers Standardization Society SP-58, 69, & 89.
  • The following criteria shall be considered in the selection of high temperature pre-insulated pipe supports:
    • Vertical, lateral and axial support design load limits.
    • Vertical, lateral, and axial support design travel limits.
    • Temperature of the support, at the pipe surface, and ambient conditions.
    • All test or pre-operational loads that may exceed normal operating conditions.
    • Any dimensional clearances needed during installation and operation should be specified.
    • Material for any items that will be welded directly to the pipe.
    • All loading and displacements caused by seismic, hydraulic surge, or other disturbances.
    • Temperature at the support steel.
  • Upon request by the purchaser or the end user, design calculations of supports will be made available for review.
  • Upon request by the purchaser or the end user, localized stress calculations for lugs and other welded attachments will be made available for review.
  • Prior to placing an order, all special requirements such as mill test reports, material certification or non-standard materials must be specified.

Design Criteria

  • The load bearing insulating materials used in the pre-insulated pipe support shall be the same material that was used to rate the support.
  • At the request of the end user or the purchaser, we will make available compressive strength and thermal conductivity testing results of the high-density calcium silicate insulation in the format provided by MSS SP-89. Testing will be done at the maximum temperature of 1200.
  • A description of the magnitude of load that can be applied to the support shall be provided for evaluation upon request. A minimum safety factor of 3 at the system design temperature shall be used to determine the maximum load.
  • Testing for compressive strength properties shall comply with ASTM D1621, the standard testing method, for compressive properties of rigid cellular insulation.
  • Testing for thermal conductivity shall comply with ASTM C165, Standard Test Method of Measuring Compressive Properties for Thermal Insulation.
  • Load-bearing element capacity shall be demonstrated at the system design temperature and load.
  • The pre-insulated pipe support assembly shall exert sufficient clamping force to ensure that the support will move axially with the pipe and will not slip under design conditions.
  • All slide plate surfaces shall be designed so that the coefficient of friction will be limited to .1 for the design life without requiring lubrication. Any friction-reducing material that requires bonding shall be bonded to a backing structure prior to shipment.
  • The lower design temperature of the unit at the pipe surface shall be 40°F (4.4°C). The maximum outside design temperature should be 140°F (60°C), the maximum pipe surface temperature should be 1800°F (982°C). For higher or lower temperatures, please contact us.
  • The required properties of the load-bearing insulating materials under design conditions are:
    • The maximum thermal conductivity is 0.77 BTU-in/hr-ft2 – °F at a mean insulation temperature of 700°F.
    • There can be a maximum of 1/32″ of non-permanent deformation under the pipe due to permanent consolidation of the load-bearing insulation.
    • There can be an additional 1/32″ of non-permanent deformation under the pipe.
  • The outside surface temperature of the unit shall not exceed 120°F when the ambient air is 140°F at all ambient temperatures.

Fabrication

  • The pre-insulated pipe support shall:
    • Come pre-assembled with sufficient insulation flushed to the outer metal jacket, allowing the pipe insulator to butt the line insulation against it.
    • Will withstand the clamping forces transferred by the cradle.
    • Will be treated to prevent moisture degradation in accordance with ASTM C656 Type I.
    • The ID and OD dimensions of the insulation shall conform to ASTM specification C585 unless otherwise specified.
  • Designs having sliding surfaces shall incorporate a stainless steel sheet metal sliding surface on the underside of the support base, over a factory-mounted and mechanically attached polyethylene slide pad on a carbon steel mounting plate, which is welded or bolted to the support steel. Teflon slide padsare optional and may be used to replace the polyethylene pads.
  • All welding shall comply with B31.3 and B31.1 Piping Code and AWS D1.1
  • The following items unless otherwise noted on contract drawings shall be in accordance with the following:
    • Structure shapes and plate: ASTM A-36
    • Bolts and studs: ASTM A-307
    • Nuts: A563
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