PSI Model C Coated Casing Spacers/Isolators

PSI coated steel casing spacers/isolators are selected when strength and excellent corrosion resistance are the most important concerns.


PSI Coated Casing Spacers/Isolators

Model C

Model G Runner

Model GN Runner

Model Options

Model C8G2 or C8GN2

Coated steel casing isolator with a 8″ (203mm) wide steel band and 2″ (50.8mm) wide glass reinforced polymer runners.

Model C12G2 or C12GN2

Coated steel casing isolator with a 12″ (305mm) wide steel band and 2″ (50.8mm) wide glass reinforced polymer runners.

Casing Spacer Model C

An extremely tough and durable heat fused fluid bed thermo set cross-linked polymer coating is offered on steel casing spacers/isolators 4″ and larger, with 8″ and 12″ band widths. The cold formed steel casing spacer/isolator band (risers where applicable) and studs for runner mounting are grit blasted, heated and fusion coated with a cross-linked epoxy polymer formulation, providing a minimum 0.010 (0.254mm) thick coating over the entire metallic surface. A post cured cycle strengthens the bond and provides an even more uniform coating.Other heat fused formulations are also available for custom orders and applications.

The runners are attached with 3/8″ diameter studs, which are fusion welded to the band before it is powder coated. They are recessed far below the wearing surface of the runner. After the runner is anchored to the band, the stud counter-bore is filled with specially formulated caulk to assure a water tight seal for the stud and the locking fastener.

Targeted Use

Energy, Water and Filled Casings

  • For carrier pipe diameters ranging from 4″ (101.6mm) to 120″ (304.8cm).
  • For carrier pipe insertion lengths up to 5,000 feet* (1,524M)
  • Spacing Recommendations: Max 8′ (243.8cm) between spacers, Max 2′ (61.0cm) from casing pipe end, Max 2′ (61.0cm) on each side of bell or mechanical joint.
  • Recommended End Seals: Model C, S, W, R and FW.

*Pipe insertion lengths may vary depending on type of casing pipe, condition of casing pipe or other factors that may cause excessive abrasion to runner materials.

Benefits and Features

  • Low Labor Costs – May Be Installed By One Person
  • Glass Reinforced Nylon or Polyester Runners Offer Low Coefficient of Friction = 0.1 to 0.6
  • Glass Reinforced Nylon or Polyester Runners Offer 18,000 PSI (1,265kg/cm?) Compressive Strength
  • Riser Height May Be Specified For Specific Positioning of Carrier Pipe Within Casing
  • Heavy Duty PVC Inner Liner Provides Protection For Pipe and/or Coating
  • Offers excellent corrosion resistance
  • May be used for long pulls and/or heavy pipe installations
  • Designed to last for the life of the piping system
  • PVC Liner Provides Back-up Isolation
  • Deeply Embossed Flanges Offer Added Strength During Tightening of Flange Bolts
  • Eliminates the Need for Blown Sand or Pea Gravel
  • Available with 8″ or 12″ bands.
  • 10 or 7 gauge risers may be ordered.

Field Terminology

psi casing spacer field terminology

Typical Road Crossing Application for Coated Casing Spacers

psi casing spacer typical application

Material Specifications for PSI Cross-Linked Epoxy Coated Metallic Casing Spacers and Isolators


14 Gauge (0.074″[1.88mm]) hot rolled and pickled mild steel.
12 Gauge (0.105″ [2.66mm]) hot rolled and pickled mild steel.
Flanges of the spacer are deep embossed and the corners are chamfered.

Liner – Polyvinyl Chloride Liner (Standard)

Thickness 0.090″ (2.29mm) minimum
Hardness Durometer “A” 85-90
Dielectric Strength
1/8″ (3.18mm) Surge Test
Step-by-Step Test
60,000 V min.
58,000 V min.
Water Absorption 1% max.
Temperature -40 to 170°F. (-40 to 76°C.)

Configurations – Band

4″ (101.6mm) through 36″ (914mm) = 2-piece
36″ (914mm) through 48″ (1,219mm) = 3-piece
48″ (1,219mm) and over = Consult Factory

Finish – 10 to 16 mil. Fusion Bonded PVC Coating

Durometer – shore D (10 sec.)
(ASTM D2240-74)
Max. Operating Temp. (constant) 225°F.
Aging Properties Excellent
Electrical Properties (ASTM
D149-97)(short time 0.010″)
1,500 V/mil.
Salt Spray (ASTM B117)


10 Gauge (0.135″ [3.43mm]) steel MIG welded to band. (standard)
7 Gauge (0.179″ [4.55mm]) steel MIG welded to band. (Contact PSI)

Liner – T.P.E. Liner (Temperature Extremes) Model C12 Only

Thickness 0.118″ (3.0mm)
Hardness Shore “A” 73
Dielectric Strength
1/8″ (3.18mm) Surge Test
Step-by-Step Test
60,000 V min.
58,000 V min.
Water Absorption 1% max.
Temperature -50 to 270°F. (-45 to 132°C.)

Configurations (Threaded Studs, Nuts and Washers)

8″ (203.2mm) Band = 6 studs, 12 nuts and washers
12″ (305mm) Band = 8 studs, 16 nuts and washers

Hardware (Threaded Studs, Nuts and Washers)

Threaded Studs = 5/16″ – 18 x 2-1/2″
304 stainless steel or plated
Hex Nuts = 5/16″
Washers = 5/16″ SAE 2330

Material Specifications for G and GN Runners

psi nylon runner Model GN

Model G Runner is a 2″ (51mm) wide Glass Reinforced Polyester Runner.

Model GN Runner is a 2″ (51mm) wide Nylon Runner.

The Nylon GN Material is the PSI Standard Material.

Effective Runner Heights and Lengths

Sizing carrier pipe O.D. and casing I.D. can be misleading at times due to a difference between nominal and effective dimensions. When sizing, make sure to consider effective runner height. Two heights are available/used; custom positioning in the casing can be achieved with riser heights.

Heights – Nominal vs Effective

2″ Wide Glass Reinforced Nylon or Polyester Runners

Nominal = 1.0″ (25.4mm) – 1.5″ (38.1mm)

Effective = 1.07″ (27.2mm) – 1.70″ (43.2mm)

Runner Specifications (G and GN)

Tensile Strength,
(ASTM D638)
17,600 psi (1,237kg/cm?)
Flexural Strength,
(ASTM D790)
25,300 psi(1,779kg/cm?)
Compression Strength,
(ASTM D695)
18,000 psi(1,266kg/cm?)
(10% Deformation)
Deflection Temp. @ 264 psi,
(ASTM D648)
405?F (205?C)

psi Polyester runner Model G

Lengths – Effective

2″ Wide Glass Reinforced Nylon or Polyester Runners

7.0″ (177.8mm) – 11.0″ (279.4mm)

Glass reinforced polymer runners are standard in 2″ (50.8mm) widths for Model C (coated). PSI GN glass reinforced nylon runners have 5 times the compressive strength of polyethylene runners. Our Model G polyester 2″ wide runners are particularly designed for heavier pipes and longer pulls.

Sizes and Configurations

The following sizes are applicable for Models G and GN

  • 4″ (101.6mm) thru 12″ (305mm) = 2 top and 2 bottom
  • 14″ (356mm) thru 36″ (914mm) = 2 top and 4 bottom
  • 38″ (965.2mm) and over = Consult Factory

How to Order Coated Casing Spacers

To order Coated Casing Isolators please indicate the following:

  1. Quantity
  2. Type Finish
  3. Band Width
  4. Runner Width
  5. Carrier Pipe O.D. (Type and coating thickness if applicable.)
  6. Casing Pipe I.D. (Type and coating thickness if applicable.)
  7. Carrier Pipe Joint O.D. (if applicable)
  8. Carrier Pipe Position within Casing
  9. Length of Crossing
  10. Contact your local distributor or Pipeline Seal & Insulator, Inc.

To order end seals please indicate the following:

  1. Quantity
  2. Model Number
  3. Carrier Pipe O.D.
  4. Coating Thickness
  5. Casing O.D.and Wall Thickness
  6. Contact Allied Corrosion Industries, Inc.

order picture order picture

Ordering Guidelines and Examples

C = Coated 8 = 8″ Band
12 = 12″ Band
G-2 = 2″ Wide Glass Reinforced Runners Indicate Actual O.D.
Including Coating
Indicate Actual O.D.
Including Coating
Indicate Actual O.D.
Including Coating
S = Standard
C = Centered
CR = Centered/Restrained
NCR = Non-centered/Restrained
EXAMPLE: Coated 12″ (305mm) wide steel band casing spacer with 2″ (50.8mm) wide glass reinforced polymer runners for a 16″ (400mm) ductile iron pipe with a 17.40″ (400mm) outside diameter within a casing pipe with a 23.25″ (590mm) inside diameter, carrier pipe joint O.D. 20.00″ (508mm), standard position.
C 12 G-2 17.40 23.25 20.00″ S

Installation Instructions for Coated Casing Spacers

Always Wear Appropriate Safety Equipment and Follow All Your Company Regulations!

In general, the actual physical insertion method is left to the expertise of the installation contractor and beyond the scope of PSI-Pipeline Seal and Insulator, Inc.
The following are suggested installation techniques and guidelines that should be taken into consideration when installing the casing spacers to the carrier pipe and handling prior to insertion.

  • It is absolutely critical that when installing the casing spacer that the spacers are lined up perfectly straight on the carrier pipe. All runners should line up straight like the sight through a gun barrel, making sure all segments of the spacer correspond to the drawing.
  • When handling the pipe it is also critical that the load is uniformly applied to all casing spacers on each joint of pipe and not just one. Furthermore, caution should be taken so they do not set the carrier pipe down with the casing spacers attached unless it is on a cut-a-way section of the casing pipe so the runners are bearing the weight uniformly. The weight should be uniformly distributed to all bottom runners at one time. Better yet, until the pipe is being installed, have the contractor place sand bags or similar material under the pipe to bear the weight.
  • The casing spacers should be uniformly tightened so that approximately 1/2″ space (by design) exists at each flange of the casing spacer. The studs at each flange should be tightened uniformly which should result in a torque reading of 60 inch-pounds (5 foot-pounds)*. Spacing between casing spacers is as detailed on the project or in accordance with the latest PSI literature.
  • It is desirable to restrict or minimize rotation or rifling of the carrier pipe within the casing unless the spacers are designed with equal length runners and specifically intended to allow for rotation.
  • Spacers are manufactured with requested clearance design. If weld beads are excessive (more than 1/4″ ) bore of casing beyond quality tolerances, bend or sags exist in the casing, these tolerances could be diminished.

*In most installations, torque wrenches are not used. The nuts are tightened on the studs sufficiently, but not so much as to bend the flanges of the casing spacers.

PDF Documents for Download

Engineering Manual Cover

Casing Spacer and End Seals

Engineering Manual and Buyers Guide

Model C Coated Casing Spacer/Isolator Specification

RFQ Interactive Form/Worksheet