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CPI 1-1/2" Flush FPT HD Spinweld Fitting - Heavy-Duty RV Tank Component
The CPI 1-1/2" Flush FPT HD Spinweld Fitting (Part # 57HD) is a premium heavy-duty tank fitting designed specifically for RV fresh water and holding tank installations. This authentic Custom Plastics (CPI) component features robust construction that exceeds standard fitting specifications, making it the ideal choice for demanding RV applications where reliability and durability are essential.
Why Choose This Heavy-Duty Spinweld Fitting
When you're installing or repairing RV tank fittings, choosing heavy-duty components ensures long-lasting performance and peace of mind on the road. This HD (Heavy-Duty) spinweld fitting from CPI is engineered with reinforced construction that withstands the vibration, temperature fluctuations, and stress of RV travel better than standard fittings. The flush-mount design provides a low-profile installation that maximizes interior tank space while the 1-1/2" female pipe thread connection ensures compatibility with standard RV plumbing components.
Technical Specifications
- Part Number: 57HD (CPI Part # 500501)
- Fitting Size: 1-1/2 inch Female Pipe Thread (FPT)
- Hole Size Required: 2-1/2 inches
- Installation Type: Flush mount spinweld
- Construction: Heavy-Duty (HD) reinforced design
- Material: High-grade plastic polymer
- Manufacturer: Custom Plastics Inc. (CPI)
- Weight: 12 oz
- Condition: Brand New OEM
- SKU: 57HD/500501
- Compatibility: RV fresh water tanks, RV holding tanks
Compatible RV Tank Applications
This versatile 1-1/2" flush FPT fitting is designed for use in both fresh water and holding tank systems. The heavy-duty construction makes it particularly well-suited for high-use applications such as main tank drains, fill connections, and vent fittings where standard components may fail over time.
If you're building or repairing a complete RV tank system, consider these complementary CPI spinweld fittings:
- 1-1/2" FPT Spinweld Fitting (Part # 56) - Standard duty version for lighter applications
- 1-1/2" Flush Spinweld Fitting w/ Membrane (Part # 57M) - Includes membrane for odor control
- 2" FPT Flush Spinweld Fitting (Part # 58) - Larger size for high-flow applications
- 1-1/4" FPT Threaded Spinweld Fitting (Part # 55) - Smaller size for vent lines
Installation and Use Cases
The spinweld installation method creates a permanent, leak-proof bond between the fitting and your RV tank. This flush-mount design sits nearly flat against the tank surface, making it ideal for installations where interior clearance is limited or where a low-profile fitting is preferred for aesthetic reasons.
Common Applications:
- Fresh water tank drain connections
- Holding tank drain fittings (black and gray water)
- Tank fill port installations
- Vent line connections
- Tank sensor wire pass-throughs
- RV tank repairs and renovations
- Custom RV tank fabrication projects
- Replacement for worn or damaged fittings
Compare 1-1/2" Spinweld Fittings
| Model | Part Number | Construction | Best For | View Details |
|---|---|---|---|---|
| 1-1/2" FPT Spinweld | 56 | Standard duty | Light-duty applications, budget builds | View Product |
| 1-1/2" Flush FPT HD | 57HD | Heavy-Duty (HD) | High-stress applications, main drains | Current Product |
| 1-1/2" Flush w/ Membrane | 57M | Standard + membrane | Holding tanks needing odor control | View Product |
Helpful Tip: Choose the HD (Heavy-Duty) version for main tank drains, high-flow applications, or anywhere you need extra strength and durability. The standard version (Part # 56) works well for secondary connections and vent lines, while the membrane version (Part # 57M) is ideal for holding tank applications where odor control is important.
Authentic CPI Quality You Can Trust
Custom Plastics Inc. (CPI) has been manufacturing premium RV tank components for decades, earning a reputation for quality and reliability in the RV industry. This 1-1/2" Flush FPT HD Spinweld Fitting represents the same level of craftsmanship and engineering that RV manufacturers trust for factory installations.
What Sets This HD Fitting Apart:
- Reinforced heavy-duty construction for extended service life
- Precision-molded threads for leak-free connections
- UV-resistant material that won't degrade in sunlight
- Chemical-resistant polymer suitable for all tank types
- Flush-mount design maximizes usable tank capacity
- 2-1/2" hole size standard for easy installation
- Compatible with all standard 1-1/2" NPT plumbing components
- Tested to withstand RV travel vibration and stress
Frequently Asked Questions
What is the difference between the HD and standard 1-1/2" fittings?
The HD (Heavy-Duty) version features reinforced construction with thicker walls and enhanced structural integrity compared to the standard Part # 56. This makes it ideal for high-stress applications like main tank drains where durability is critical.
What size hole do I need to drill for this fitting?
This fitting requires a 2-1/2 inch diameter hole for proper installation. The spinweld process creates a permanent bond between the fitting and the tank material.
Can this fitting be used on both fresh water and holding tanks?
Yes, this CPI fitting is designed for use on both fresh water tanks and holding tanks (black and gray water). The chemical-resistant material is suitable for all RV tank applications.
Is this a flush mount or raised fitting?
This is a flush-mount fitting, meaning it sits nearly flat against the tank surface with minimal protrusion into the tank interior. This design maximizes usable tank capacity.
What does FPT mean?
FPT stands for Female Pipe Thread. This fitting has internal (female) threads that accept standard 1-1/2" male NPT pipe fittings, valves, or adapters.
How do I install a spinweld fitting?
Spinweld fittings require a specialized spin welding tool that rotates the fitting at high speed to generate friction heat, melting the plastic and creating a permanent bond with the tank. This is typically done during tank manufacturing or by professional tank fabricators.
Customer Reviews Highlight Quality and Performance
With an impressive 5.0-star rating from 8 verified customer reviews, this CPI fitting has earned high marks for quality, fitment, and value. Customers consistently praise the heavy-duty construction, perfect fit, and fast shipping. Many reviewers mention successful use in RV renovation projects and tank repair applications.
Order Your Authentic CPI Fitting Today
Whether you're building a custom RV tank system, repairing existing tanks, or upgrading to heavy-duty components, this CPI 1-1/2" Flush FPT HD Spinweld Fitting delivers the quality and reliability you need. Fast shipping, authentic OEM quality, and expert support make Elkhart RV Parts your trusted source for RV tank fittings.
Need help selecting the right fitting for your project? Use our AI Live Chat for deep product knowledge and expert assistance with compatibility questions.
Ready to upgrade to heavy-duty quality? Add this authentic CPI 1-1/2" Flush FPT HD Spinweld Fitting to your cart now and experience the difference that professional-grade components make.
| Material | Plastic |
|---|---|
| Hole size (inches) | 2.5 |
| Fitting size (inches) | 1.5 |
- What size hole is required for installing the 1-1/2" flush fpt hd spinweld fitting? The fitting requires a 2 1/2" hole size for installation.
- Is this fitting compatible with rv fresh water and holding tanks? Yes, this Spinweld fitting is designed for RV fresh water and holding tanks.
- What does fpt stand for in the product title? FPT stands for Female Pipe Thread, indicating the type of threading on the fitting.
- Who is the vendor for the 1-1/2" flush fpt hd spinweld fitting? The vendor for this product is CPI.
- Is this product new or used? This product is new.
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