6 Best Bulkhead Fittings For RV Fresh Water Tanks Nomads Swear By
A reliable bulkhead fitting is crucial for a leak-free RV. We review the 6 best options nomads trust for a secure, long-lasting, watertight seal.
You hear it before you see it: the faint, rhythmic drip-drip-drip from under your dinette. A tiny puddle is forming, threatening your subfloor, your sanity, and your access to 40 gallons of fresh water. The culprit is often one of the smallest, cheapest parts of your entire plumbing system—a failed bulkhead fitting. Choosing the right one isn’t just about plumbing; it’s about protecting your rig and ensuring you have water when you’re miles from the nearest city.
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Why Quality Bulkhead Fittings Matter in Your Rig
A bulkhead fitting is a simple component with a critical job. It creates a waterproof, threaded port through the wall of your water tank, allowing you to connect pipes for filling, draining, or drawing water to your pump. Think of it as the gatekeeper for every drop of water you carry.
When one fails, the consequences are never small. A slow leak can go unnoticed for weeks, silently rotting your floor and feeding mold. A catastrophic failure can dump your entire fresh water supply in minutes, leaving you high and dry and potentially causing thousands in water damage. This isn’t a place to save five dollars.
The stress on these fittings is immense. They endure constant vibration while driving, temperature swings from freezing nights to scorching desert days, and the pressure of sloshing water. A cheap, brittle plastic fitting from a big-box store simply isn’t engineered for this abuse. Investing in a quality fitting is investing in the long-term health and reliability of your entire home on wheels.
Banjo Polypropylene Bulkhead: The Go-To Choice
This Banjo bulkhead tank fitting connects pipes and hoses with its durable polypropylene construction and 2" NPT female threads. Made in the USA, it ensures reliable fluid transfer for your tank applications.
If you ask a dozen seasoned van builders or full-time RVers what fitting they trust, a majority will say "Banjo." These fittings aren’t from the RV world; they come from the agricultural and chemical industries, where failure is not an option. They are built to handle corrosive fertilizers and withstand daily abuse, which makes them wonderfully over-engineered for an RV fresh water tank.
Their signature is glass-reinforced polypropylene construction. This material is incredibly tough, resistant to UV degradation, and won’t get brittle in the cold or soft in the heat. It’s a true four-season solution. Paired with a thick, high-quality EPDM gasket, Banjo fittings create a seal you can count on for years.
The peace of mind is what you’re really buying. When you’re tightening down a Banjo fitting, you can feel the quality in the thick, precise threads. It doesn’t feel like it’s about to crack. For a critical connection point that’s often buried behind panels, "install it and forget it" is the ultimate goal, and Banjo delivers.
Spears Schedule 80 PVC: Heavy-Duty Reliability
When your setup demands maximum durability, Spears is the answer. You’ll recognize Schedule 80 PVC by its dark gray color and noticeably thicker walls compared to the standard white PVC (Schedule 40) you see in home improvement stores. This is industrial-grade stuff, designed for high-pressure water mains and chemical processing plants.
The primary advantage of a Spears Sch 80 fitting is its sheer brute strength. If your tank is mounted externally, like on the undercarriage of a skoolie or truck camper, this fitting can take a hit from road debris without cracking. It’s the choice for builds where the plumbing is exposed to the elements or potential physical damage.
The trade-off is in the installation. Schedule 80 fittings are part of a solvent-weld system, meaning you’ll be using PVC primer and cement to make your connections. This creates an incredibly strong, permanent bond, but it’s less forgiving than threaded fittings if you make a mistake. It’s a more committed installation, but for rugged, exposed applications, its reliability is unmatched.
Valterra Slip x FPT: The RV Plumbing Standard
Walk through any RV parts store and you’ll be surrounded by Valterra products. They are a cornerstone of the RV industry, and their bulkhead fittings are what you’ll find installed in countless factory-built travel trailers and motorhomes. They represent a reliable, well-understood industry standard.
Many Valterra fittings come in a "Slip x FPT" configuration. This means the inside (wet side) of the fitting has a smooth slip socket for gluing a PVC pipe, while the outside has Female Pipe Threads (FPT). This hybrid design gives you options, allowing you to connect to a PEX adapter or other threaded plumbing components easily.
While not as robust as a Banjo or a Spears Sch 80, a Valterra fitting is more than adequate for the vast majority of RV applications. It’s a cost-effective, widely available, and proven solution, especially for tanks located inside a protected bay or under a dinette. For a simple replacement on a standard RV, you can’t go wrong sticking with the brand the manufacturer trusted.
Hayward PVC Bulkhead: A Trusted Industry Name
This Hayward bulkhead fitting ensures secure plumbing connections with its durable PVC construction and reliable EPDM seals. Designed for 150 PSI maximum pressure, it features a 4" socket x threaded end for versatile installation.
Like Banjo and Spears, Hayward is another brand that built its reputation in a tougher industry: pool and spa systems. Their components are designed to live in a chemically treated, high-flow water environment 24/7, which makes them an excellent choice for a durable RV water system.
One of Hayward’s standout design features is the use of a left-hand thread on the main body. This is a small but brilliant detail. It means that as you tighten a standard right-hand threaded pipe or valve onto the outside of the fitting, you are simultaneously tightening the fitting’s nut against the tank wall. It’s a clever bit of engineering that prevents the entire bulkhead from spinning in its hole during installation.
These fittings are known for their precision molding and high-quality gaskets, leading to a very reliable seal. If you’re looking for an industrial-quality PVC option with thoughtful design features, Hayward is a top-tier contender that provides an extra layer of installation security.
Dixon Valve Brass Fitting: A Durable Metal Option
Sometimes, plastic just won’t cut it. For high-stress connection points, like a main drain valve that gets operated frequently or is exposed on the vehicle’s exterior, a brass bulkhead fitting offers a significant step up in durability. Metal simply provides a level of strength and impact resistance that plastics can’t match.
The main benefit is in the threads. It’s nearly impossible to cross-thread or crack a brass fitting from over-tightening. This makes it ideal for connections that you might need to assemble and disassemble periodically. If you want to attach a heavy brass ball valve for a drain, connecting it to a brass bulkhead ensures a rock-solid, all-metal connection point.
The downsides are cost and weight. Brass fittings are considerably more expensive and heavier than their plastic counterparts. While modern lead-free brass is perfectly safe for potable water, some purists still prefer plastic for their fresh water supply to eliminate any possibility of a metallic taste. Use brass strategically where its strength is a genuine asset.
Class A Customs Fittings for DIY Tank Setups
For the DIY van, bus, or tiny home builder, Class A Customs is a name you need to know. They specialize in the components for custom water systems, offering a huge variety of tanks and the specific fittings designed to work with them. They’ve become the de facto source for the conversion community.
Their value isn’t just in the quality of their fittings, which are typically robust PVC or ABS parts, but in the integrated ecosystem they provide. When you buy a tank and fittings from the same place, you eliminate the guesswork. You know the fitting is compatible with the tank’s wall thickness and curvature, and you can often find kits that include the correct hole saw size.
This one-stop-shop approach simplifies the most intimidating part of a custom build. Instead of hunting down individual components and hoping they match, you get a proven system. Their fittings are no-nonsense, reliable parts that form the backbone of thousands of successful DIY water systems on the road today.
Pro Tips for a Leak-Proof Bulkhead Installation
Getting the right fitting is only half the battle. A perfect installation is what guarantees a dry floor. After installing hundreds of these, I’ve learned that the details make all the difference.
- Drill a Clean Hole. Use a sharp hole saw of the exact size recommended for your fitting. After drilling, carefully remove any plastic burrs from the edge of the hole with a utility knife or deburring tool. A tiny plastic remnant can prevent the gasket from seating properly.
- Gasket on the Inside. This is the golden rule. The rubber gasket always goes on the wet side of the tank. Water pressure will then push the gasket tighter against the tank wall, strengthening the seal. Installing it on the outside is the number one cause of leaks.
- Hand-Tight Plus a Quarter Turn. Do not use all your strength. Over-tightening can crack the fitting, warp the tank wall, or squeeze the gasket out of place. The proper technique is to tighten the nut by hand until it’s snug, then use a wrench for a final quarter-turn. That’s it.
- No Sealant on the Gasket. A quality fitting does not need silicone or pipe dope on the gasket. In fact, sealants can lubricate the gasket, allowing it to slip out of place and cause a leak. If you want to use a thread sealant, apply a small amount to the threads of the nut only to prevent it from seizing, never on the sealing surface of the gasket itself.
Your RV’s water system is a network of dependencies, and its integrity starts at the tank. A bulkhead fitting might seem like a minor detail, but it’s a foundational component that enables everything else. By choosing a fitting designed for the job—whether it’s an industrial Banjo for peace of mind or a rugged Spears for an under-mount tank—you’re making a smart investment in a reliable, leak-free life on the road.
