CPI 3" Flex Black Rubber Tank Fitting - Professional Grade RV Plumbing Solution

The CPI 3" Flex Black Rubber Tank Fitting (Part # 93 / 500125) is a professional-grade grommet designed specifically for plumbing connections into RV black water and grey water holding tanks. This flexible rubber fitting accommodates a 3 7/8" hole size and provides a secure, leak-resistant seal for 3-inch plumbing applications.

Why Choose This CPI Flex Tank Fitting

CPI has been manufacturing premium RV tank fittings for decades, and this 3" flex fitting represents their commitment to quality and reliability. The flexible black rubber construction allows for easier installation while maintaining a watertight seal, even when dealing with slight misalignments or tank wall irregularities. This fitting is engineered to withstand the harsh conditions of RV waste systems, including temperature fluctuations, chemical exposure, and constant vibration during travel.

Key Features and Benefits

This 3" flex fitting features durable black rubber construction that resists cracking and degradation from waste tank chemicals. The flexible design accommodates minor installation variations and provides stress relief that rigid fittings cannot match. With a 3 7/8" hole size requirement, this fitting installs quickly using standard hole saws, and the rubber material creates a compression seal that prevents leaks without requiring extensive sealant application.

The fitting's 3-inch diameter is ideal for main tank outlets, drain connections, and larger vent applications. The black rubber material is UV-resistant and maintains its flexibility across a wide temperature range, ensuring reliable performance whether you're camping in Arizona summers or Minnesota winters.

Technical Specifications

Part Number: 93 (500125)
Manufacturer: CPI
Fitting Diameter: 3 inches
Required Hole Size: 3 7/8 inches (3.875")
Material: Black Rubber
Application: RV Black & Grey Water Holding Tanks
Weight: 0.7 lbs
Barcode: 46409787

Installation and Compatibility

This flex fitting is designed for use with standard 3-inch PVC or ABS plumbing pipes commonly found in RV waste systems. Installation requires drilling a 3 7/8" hole in the tank wall, inserting the fitting, and securing it according to manufacturer specifications. The flexible rubber design allows for some angular adjustment during installation, making it easier to align with existing plumbing runs.

This fitting is compatible with most RV holding tank materials including polyethylene, polypropylene, and ABS plastic tanks. It works with both black water and grey water applications and can be used for tank outlets, drain connections, or large-diameter vent installations.

Complete Your Tank Fitting Setup

For comprehensive tank plumbing solutions, consider these compatible CPI fittings: The CPI 1-1/2" Tank Grommet Fitting (Part 91) is perfect for smaller inlet or vent connections. For 2-inch applications, the 2" Flex Fitting (Part 92) offers the same flexible design in a smaller size. Don't forget specialized RV tank sealant to ensure a completely leak-proof installation.

Compare 3" Tank Fitting Options

Model	Type	Hole Size	Part Number	Best For	View Details
CPI Part 93	Flex Rubber Fitting	3 7/8"	93 (500125)	Flexible installation, main outlets	Current Product
Uniseal U300	Grommet Seal	4"	U300	Watertight seal, Schedule 40 PVC	View Details
CPI Part 92	Flex Rubber Fitting	2 3/4"	92	2" applications, smaller outlets	View Details

Pro Tip: Choose flex rubber fittings like the CPI Part 93 when you need installation flexibility and stress relief. Uniseal grommets work best when you need a permanent watertight seal with Schedule 40 PVC pipe.

Why Buy From Elkhart RV Parts

When you purchase this CPI 3" flex fitting from Elkhart RV Parts, you're getting an authentic OEM-grade component backed by our commitment to quality. We stock genuine CPI parts and ship them quickly so you can complete your RV repairs without delay. Our team understands RV plumbing systems and can help ensure you're ordering the correct fitting for your specific application.

With an average customer rating of 4.6 out of 5 stars based on 9 reviews, this fitting has proven its reliability in real-world RV applications. Customers appreciate the quality construction, ease of installation, and long-lasting performance.

Frequently Asked Questions

What size hole do I need for this 3" flex fitting?

This fitting requires a 3 7/8" (3.875 inch) hole. Use a 3 7/8" hole saw for accurate installation.

Can this fitting be used for both black and grey water tanks?

Yes, this CPI flex fitting is suitable for both black water and grey water holding tank applications.

Do I need sealant with this rubber fitting?

While the rubber creates a compression seal, we recommend using specialized RV tank sealant for maximum leak protection, especially on older tanks or in high-stress applications.

Will this work with 3" PVC pipe?

Yes, this fitting is designed to work with standard 3-inch PVC or ABS plumbing pipes commonly used in RV waste systems.

Order Your CPI 3" Flex Tank Fitting Today

Don't let a faulty tank fitting compromise your RV's waste system. Order this genuine CPI 3" flex black rubber tank fitting today and enjoy fast shipping, authentic OEM quality, and the peace of mind that comes with proper RV plumbing components. For questions about compatibility or installation, use our AI Live Chat for expert product guidance.

CPI Grommets

CPI - 3" Flex Black Rubber Tank Fitting - 3 7/8" Hole Size - Part # 93 (500125)

2" Flex Fitting 2 3/4" Hole Size Part # 92

CPI - 1-1/2" RV Tank Grommet Fitting - 2-1/4" Hole - Part 91 (500123)

Rubber Tank Grommet 2" (Slip 2-5/8")