Common Questions
RACI casing spacers are made of interlocking HDPE segments with no metal bolts or attachments. Engineered with high impact strength and a low coefficient of friction, they guarantee the reliability and success of your underground infrastructure projects.
Engineered for durability and precision, RACI casing spacers provide long-term support for underground piping systems—with published load ratings and corrosion-resistant HDPE that performs where steel falls short.
General Casing Spacer Questions
1. Why use casing spacers instead of wood skids?
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.
2. What is the difference between centering and restraining?
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.
3. Do all installations require the carrier pipe to be centered and restrained?
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.
4. Can RACI spacers be used in both dry bores and grouted installations?
Yes. RACI spacers are designed for both dry bores and grouted installations. Their runners allow grout to flow smoothly without creating voids or obstructions.
5. What kind of loads can your spacers handle?
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.
6. Are RACI casing spacers compliant with ASTM and ISO standards?
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.
7. How far apart should spacers be installed?
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.
8. Can spacers be installed on ductile iron, HDPE, or PVC pipes?
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.
9. Are RACI spacers approved by municipalities or government agencies?
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.
10. How long do the spacers last?
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
1. How quickly can orders ship out?
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.
2. Can you provide submittals or documentation for project approval?
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.
3. How do I know what spacer model and height to choose?
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.
4. What information do I need to request a quote?
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
5. Can you support multiple carrier pipes in one casing?
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.
6. Can RACI spacers be customized for special applications?
Yes. Custom spacer configurations can be provided on a project-by-project basis. Contact us with your application details to explore options.
7. What runner heights are available? Can you do low-clearance configurations?
Runner heights range from 0.59″ to 7.87″. RACI’s modular design allows for low-clearance solutions and tight-tolerance applications.
8. How are the spacers secured to the pipe? What kind of tape is used?
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.
9. Does Public Works Products offer emergency assistance?
Yes. For after-hours, weekend, or emergency service, contact us and someone from our team will respond immediately.
