RACI HDPE Casing Spacers - Pipe Protection & Alignment Solutions
Yes
No
Varies¹1 Other plastic spacers may contain metal elements that will rust over time, resulting in a structurally compromised spacer.
2 Wood skids don't corrode, but they are prone to rotting and termites.
Global Leader
Since 1952, with no reported failures to date
100% HDPE
Corrosion-resistant & non-metallic
Modular Design
Fits any size, easily adjusted
Wide Range
OD sizes from 1.65" to 134"+
Tested Loads
Real, published data
Constant Support
360° coverage ensures stability regardless of pipe rotation
No Pipe Damage
Soft contact, no sharp edges
One-Person Install
Lightweight & efficient
In-Stock
Largest stock in North America — ready to ship same day
- Casing spacers shall be modular, projection-type segments made from high-density polyethylene (HDPE), assembled around the carrier pipe to provide uniform support and alignment.
- The number of projections (runners) shall be equal to or greater than the carrier pipe's nominal diameter in inches (e.g., 8" pipe requires a minimum of 8 runners).
- Spacers shall be designed to center or restrain the carrier pipe within the casing unless otherwise noted on the project drawings. Extensions may be used where necessary to maintain alignment or prevent flotation.
- Spacers must provide a minimum clearance of 0.6" between the spacer outer diameter (OD) and the casing inner diameter (ID), and must also clear the bell end of the pipe by a minimum of 0.6".
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Spacers should always be able to support the weight of the
carrier pipe when filled with liquid. As a general
guideline, place spacers 2 feet from each side of the bell
joint, use double spacers at each end of the casing, and
follow these spacing recommendations:
- Water Lines: Maximum spacing of 8 feet for pipes up to 30" in diameter (3 per 20-foot segment), and 5 feet for pipes 30" and larger (4 per 20-foot segment).
- Sewer Lines: Maximum spacing of 5 feet (3 per 14-foot segment).
- Spacers shall be installed using double-sided tape provided by the manufacturer to prevent movement during insertion.
- Spacers shall be ISO 9001:2000 certified and manufactured by RACI. For assistance with sizing and selection, contact Public Works Products Inc., Dallas, TX.
RACI casing spacers protect carrier pipes and mechanical restraints from contact with the casing, helping to reduce wear and stress in water distribution and transmission mains.
- Prevents bell joints and fittings from rubbing against the casing wall.
- Keeps the pipe centered to reduce vertical movement or instability—especially over long spans or in dynamic flow systems.
- Helps maintain alignment in large-diameter transmission mains, reducing mechanical stress.
- Spacer selection considers pipe weight (including water content) to ensure long-term performance.
- Reduces friction during installation for smoother, safer placement.
Proper grade is critical in gravity sewer systems to maintain consistent flow and prevent backflow. RACI casing spacers ensure stable, centered pipe alignment from installation through operation.
- Maintains grade by keeping the pipe centered inside the casing.
- Prevents sagging and point loading by evenly distributing the pipe's weight.
- Supports long-term stability in soft or unstable soils.
- Protects against misalignment that could disrupt system performance.
In dual-containment systems, the carrier pipe must be perfectly centered to maintain flow paths, and ensure containment integrity. RACI spacers offer a safe, stable, and chemical-resistant solution.
- Prevents spacer "bundling" at one end during transport or pull-in
- Installs in minutes—no on-site fabrication required
- Maintains centering to avoid wear, misalignment or electrical shorting
- Custom material options for thermal or chemical resistance
- Compatible with HDPE, PVC, steel, and specialty materials.
- Reduces risk of failure in critical chemical or thermal applications.
HDD installs demand constant support through twists, turns and long pulls. RACI spacers maintain full pipe support—no matter how the carrier rotates—while running low-profile in tight casings and minimizing pullback friction.
- Continuous 360° support—even when the pipe twists during pullback
- Ultra low-profile runners (down to 0.7") for tight casing-to-pipe clearances
- Low-friction design for long-distance pulls without added drag
- High structural integrity to withstand HDD stresses over miles
In oil & gas pipelines, carrier-pipe longevity and safety are mission-critical. RACI casing spacers use non-corrosive HDPE to protect steel pipes, reduce wear and ensure precise alignment—onshore or offshore.
- Non-corrosive HDPE provides an extra line of defense against corrosion
- High load-bearing capacity supports heavy steel carrier pipes without deformation
- Engineered to fit a range of pipe diameters—including insulated steel pipes—without requiring customization
- Maintains precise alignment through dynamic pressure and temperature cycles
Projects involving multiple carrier pipes within a single casing typically require custom-fabricated spacers, leading to long lead times and limited flexibility. RACI offers modular casing spacers that can be adapted to support multiple carrier pipe configurations—many of which are available from stock. Whether pipes are arranged in a horizontal, vertical, or triangular pattern, we can work with you to design and supply a solution that reduces project delays and ensures structural integrity.
- Modular components available from stock—no need for full custom fabrication.
- Capable of supporting multiple pipes in various layouts within a single casing.
- Ideal for telecommunications, district energy, or any multi-line utility crossing.
- Engineering assistance available to review layouts and recommend optimal configurations.
Product Literature
Brochure (EN)
View & Download
Installation Manual (EN)
View & Download
Brochure (ES)
View & Download
Installation Manual (ES)
View & DownloadOnline Sizing Calculator
Use our interactive sizing calculator to determine the ideal spacer configuration for your project:
Sizing Calculator – Visualize Configuration in Real-Time
Launch CalculatorGeneral Casing Spacer Questions
Casing spacers ensure proper grade and alignment. Wood skids can rot, shift, or attract termites — causing unbalanced support that risks pipe damage or misalignment. Spacers give consistent, long-term protection.
Centering means keeping the carrier pipe evenly spaced within the casing. Restraint refers to limiting vertical movement. Most centered pipes are restrained, but not all restrained pipes are centered. RACI recommends at least 0.6" of clearance to avoid binding during installation.
Centering or restraining is critical for sewer lines and recommended for water lines. Sewer pipes must stay fixed to prevent floating, which can cause sediment buildup or backflow. Water pipes should also be restrained to avoid movement from pressure changes that may lead to wear over time.
Yes. RACI spacers are designed for both dry bores and grouted installations. Their runners allow grout to flow smoothly without creating voids or obstructions.
Load capacity depends on the model, but our strongest spacers support up to 11,000 lbs. Our sizing tool (www.pwpracisizing.com) and quote process both account for pipe weight when full of water, and recommend tighter spacing if needed.
RACI casing spacers are manufactured in an ISO 9001-certified facility. They are tested in accordance with relevant ASTM standards, including ASTM D638 for tensile properties and ASTM D2240 for hardness. A full list of tested properties is available in our brochure. An ISO 9001 certificate is available upon request.
Spacers are typically installed every 5 to 8 feet, depending on pipe size, weight, and application. Even though the spacers are load-rated, proper spacing is key to preventing pipe sagging or long-term wear.
Yes. Our spacers work with all pipe types, including ductile iron, HDPE, and PVC. Because they're made entirely of HDPE, they also eliminate the risk of electrical conductivity between the pipe and casing.
Yes. RACI spacers are approved by many municipalities and agencies across the U.S. and internationally. If you're unsure about your project's approval status, reach out to us through our contact page and we'll help confirm.
When properly installed, RACI spacers are designed to outlast the life of the pipe. They require no maintenance and are unaffected by corrosion or soil conditions.
Ordering, Installation & Technical Support
For most orders, Public Works can offer same-day shipping if received before 2 PM. Larger or complex orders are typically prepared for next-day shipment.
Yes. We can provide submittals, letters of compliance, and formal request letters for approval. If needed, we also offer application-specific submittals tailored to the project or municipality to help get our products approved.
Spacer selection depends on project specs, but as a rule of thumb, spacers should clear any bells or restraints by at least 0.6", and maintain a minimum 0.6" clearance between the spacer OD and casing ID. Length and casing condition may also affect the final selection. You can use our online sizing calculator to enter your details and view available spacer options.
At a minimum, please provide:
- Carrier pipe type and size (include restrainer OD if used)
- Casing pipe type and size
- Length of bore
For best results, also include:
- Project details (location, specs)
- Whether pipe needs to be centered, restrained, or just clear the bell
Yes. RACI spacers can often support multiple carrier pipes in a single casing. Our engineering team will review the layout and recommend a solution based on your project needs.
Yes. Custom spacer configurations can be provided on a project-by-project basis. Contact us with your application details to explore options.
Runner heights range from 0.59" to 7.87". RACI's modular design allows for low-clearance solutions and tight-tolerance applications.
Each spacer comes with double-sided butyl tape, enough to wrap fully around the carrier pipe. Once installed, the spacers stay securely in place and will not slide during insertion. Tape adhesion test results are available upon request.
Yes. For after-hours, weekend, or emergency service, contact us and someone from our team will respond immediately.
