跳到内容 Bulkhead pipe fittings—also called fitting bulkhead, bulkhead connectors, or tank bulkhead fittings—play a crucial role in tanks, containers, plumbing systems, and industrial fluid transfer setups. They allow a secure, leak-free connection through a tank wall or panel, letting liquids safely pass from one side to the other.
When made from 316 stainless steel, bulkhead pipe fittings offer exceptional corrosion resistance and durability, making them ideal for water treatment, chemical processing, agriculture, metal finishing, marine environments, industrial plants, and any application where reliability truly matters.
In this guide, we’ll walk through everything you need to know: what bulkhead pipe fittings are, how they’re made, why stainless steel is the preferred material, how they’re installed, and where they’re commonly used. If you are looking for a practical, real-world explanation written in natural language, this article is for you.
A bulkhead pipe fitting is a specialized connector designed to pass through the wall of a tank, drum, container, barrel, IBC tote, or reservoir. It creates a watertight and pressure-resistant seal around a drilled hole, allowing plumbing components to be attached on both sides.
Unlike standard pipe fittings, a fitting bulkhead includes:
A threaded body (usually stainless steel)
A sealing gasket (EPDM, Viton, or PTFE)
A locking nut
Internal or external NPT threads for pipe connection
Its purpose is simple:
Create a leak-proof connection through a flat or curved surface while maintaining the structural integrity of the container.
Bulkhead pipe fittings are widely used in water tanks, rainwater harvesting, irrigation systems, chemical storage, and industrial pipelines.
While bulkhead fittings come in PVC, brass, and polypropylene, more engineers and buyers are shifting toward stainless steel—especially 316 stainless steel. Why?
Because stainless steel offers unmatched:
Corrosion resistance (against water, chemical solutions, acidic fluids, seawater)
Mechanical strength
Pressure tolerance
Heat resistance
Longevity
It is the preferred material in industrial systems where safety and reliability are non-negotiable.
Most stainless steel bulkhead fittings maintain their natural metallic finish. They are not plated or coated because:
Stainless steel already has high corrosion resistance
Surface coatings may weaken the natural protection
A raw, polished stainless surface ensures lifetime stability
Ultrasonic cleaning removes machining oils and prepares the part for assembly
This clean, uncoated finish is ideal for food-grade, chemical-grade, and industrial environments.
Manufacturing typically involves:
The stainless steel bar stock is machined into precise shapes.
Threads are cut using high-accuracy turning equipment to ensure leak-free assembly.
After machining, parts are placed in an ultrasonic cleaning tank to remove:
Metal shavings
Cutting oil
Dust
Debris
This ensures a clean metal surface for proper sealing.
EPDM or Viton gaskets are matched with the body. Locknuts are fitted and inspected manually.
The result is a high-precision bulkhead pipe fitting ready for installation in demanding environments.
Bulkhead fittings come in several variations based on connection type, thread type, and application.
Female NPT bulkhead – most common
Male NPT bulkhead
Double-female connectors
Female to male variations
Straight bulkhead pipe fitting
90-degree bulkhead
Bulkhead union
Bulkhead to hose barb adapter
3/8″
1/2″
3/4″
1″
1-1/2″
2″
Larger industrial sizes up to 3″
The most commonly used size worldwide for tanks is 3/4” and 1” stainless steel bulkhead fittings.
316 stainless steel contains molybdenum, which gives it enhanced protection against:
Saltwater
Chlorides
Acids
Industrial chemicals
Cleaning agents
Perfect for harsh environments.
Bulkhead fittings withstand internal tank pressure, pump pressure, and mechanical stress without cracking or warping.
Stainless steel outlasts PVC and brass, especially in:
Outdoor installations
High-temperature systems
Chemical tanks
Suitable for:
Acids
Alkalis
Solvents
Oils
Additives
Process chemicals
With high-quality EPDM or Viton gaskets, the seal remains tight and reliable for long-term use.
Bulkhead pipe fittings are used anywhere a fluid needs to pass through a tank wall or system panel.
Poly tanks
Metal tanks
Rainwater barrels
Sump tanks
Aquaponics systems
Stainless steel is perfect for outdoor exposure.
Acid tanks
Electroplating baths
Pickling tanks
Chemical dosing systems
Waste liquid management
Because of strong corrosion resistance, 316 stainless steel is widely used in chemical plants.
Fertilizer mixing tanks
Irrigation pump outlets
Farm water storage
Saltwater rapidly degrades brass and plastic, but stainless steel holds strong.
Mixing vessels
Storage tanks
Transfer pipelines
Stainless steel’s hygiene properties are critical for food-grade environments.
Drill the correct hole size
Use a hole saw or step bit.
Example: A 3/4″ NPT bulkhead fitting often requires a 1-1/4” to 1-5/16” hole.
Insert the bulkhead from the inside
Make sure the gasket is on the inside wall for a better seal.
Position the gasket correctly
The flat side of the gasket should sit flush against the tank wall.
Tighten the locknut from the outside
Hand-tighten first, then use a wrench carefully to avoid overstressing the tank.
Attach pipe or hose fittings
NPT threads require sealing tape or pipe sealant for best results.
Test for leaks
Fill the tank or pressurize the system slightly to ensure no drips are present.
Over-tightening the nut
Using the wrong gasket material
Installing the gasket on the wrong side
Cross-threading the pipe
Drilling an inaccurate hole size
A simple, well-installed fitting bulkhead can last for decades.
Longest lifespan
Highest strength
Chemical and saltwater resistant
Ideal for industrial or harsh environments
Good for water
Not ideal for chemicals or seawater
Lower corrosion resistance
Low cost
Easy to install
Not suitable for pressure, heat, or chemicals
If reliability matters, stainless steel is always the top choice.
Q: What size bulkhead pipe fitting do I need?
Choose based on your tank outlet size and the pipe you plan to connect—usually 3/4″, 1″, or 2″.
Q: Are stainless steel bulkhead fittings better than plastic?
Yes—stronger, longer-lasting, and more chemical-resistant.
Q: Can stainless bulkhead fittings be installed on curved tanks?
Yes, as long as the curve is not too steep and the gasket seats properly.
Q: Do stainless steel bulkheads require plating?
No. Stainless steel stays in its natural finish because it is inherently corrosion-resistant.
Q: Are they compatible with chemicals?
316 stainless steel is one of the most chemical-resistant grades available.
Stainless steel bulkhead pipe fittings are the most reliable and long-lasting solution for creating leak-free tank connections. Their natural corrosion resistance, strength, and high-temperature tolerance make them ideal for water tanks, chemical plants, agriculture, marine use, and industrial systems.
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