If your air compressor constantly runs out of air before you finish a job, you’re not alone. Many DIYers and even shop owners face this problem. One practical solution is coupling two air tanks together. This setup increases total storage capacity, giving your tools more run time and reducing how often your compressor cycles on and off.
But how do you safely connect two tanks? What fittings do you need? And is it always better to add a second tank instead of upgrading to a bigger compressor? In this guide, we’ll cover everything you need to know about coupling tanks and recommend the best accessories to make the process easy and safe.
Quick Picks: Best Accessories for Coupling Air Tanks
- Best Overall: Milton S-682 Air Tank Manifold Kit – Easy-to-install kit with multiple ports for safe tank coupling.
- Best Budget: WYNNsky Brass 1/4″ NPT Coupler Set – Affordable way to link tanks with standard fittings.
- Best Premium: RapidAir MaxLine 3/4″ Air Piping Kit – Professional-grade setup for shops coupling large tanks together.
Why Couple Two Air Tanks Together?
Adding a second tank doesn’t increase your compressor’s SCFM (airflow output), but it does increase storage. Here’s what that means in practice:
- Longer Tool Run Time: Your air tools can run longer before the compressor cycles.
- Reduced Wear: The compressor doesn’t start and stop as often, extending motor life.
- Smoother Air Delivery: Larger air reserve reduces pressure drops during tool use.
- Budget-Friendly: Adding a tank is often cheaper than buying a new compressor.
Buyer’s Guide: How to Couple Two Tanks
To safely connect two tanks, you’ll need the right fittings. Here are the key things to consider:
- Tank Compatibility: Ensure both tanks have compatible NPT ports (usually 1/4″ or 3/8″).
- Check Valves: Prevents backflow and ensures tanks equalize properly.
- Hose Diameter: Use at least 3/8″ hose for good airflow between tanks.
- Safety Valves: Each tank should have a relief valve to prevent overpressure.
- Drain Valves: Both tanks must be drained regularly to avoid moisture buildup.
Detailed Product Reviews
1. Milton S-682 Air Tank Manifold Kit
Who it’s for: DIYers and shop users who want an easy, reliable connection system.
- Key Benefits: Multi-port manifold, heavy-duty brass fittings, easy setup.
- Pros: Rugged, versatile, prevents leaks.
- Cons: Slightly more expensive than DIY fittings.
Final Verdict: The best all-around solution for coupling tanks. Check Price
2. WYNNsky Brass 1/4″ NPT Coupler Set
Who it’s for: Budget buyers who just want to link two small tanks together.
- Key Benefits: Simple brass fittings, affordable kit, leak-resistant.
- Pros: Inexpensive, easy to find, durable brass construction.
- Cons: Limited to smaller setups, not ideal for shop-grade systems.
Final Verdict: Best for hobbyists and portable compressors. See Price
3. RapidAir MaxLine 3/4″ Air Piping Kit
Who it’s for: Shops coupling large stationary tanks for multiple users.
- Key Benefits: Professional-grade aluminum piping, leak-free connections, scalable system.
- Pros: Heavy-duty, long-lasting, perfect for permanent shop setups.
- Cons: Requires more installation work.
Final Verdict: Best premium system for serious shop owners. Check Price
4. Campbell Hausfeld Portable 11-Gallon Auxiliary Tank
Who it’s for: DIYers who want extra storage without upgrading compressors.
- Key Benefits: Adds capacity, portable, comes with fittings for easy hookup.
- Pros: Affordable, durable steel tank, portable design.
- Cons: Smaller than shop tanks.
Final Verdict: A simple add-on tank that’s easy to connect. View Price
5. Hromee Air Tank Accessory Kit
Who it’s for: Users who need fittings, gauges, and hoses for tank setups.
- Key Benefits: Includes safety valve, couplers, gauge, and fittings.
- Pros: Complete starter kit, affordable, easy setup.
- Cons: Quality not as high as industrial-grade kits.
Final Verdict: Great starter kit for home users coupling tanks. See Price
6. DeWalt DXCM024-0344 Hose & Fitting Kit
Who it’s for: DIYers who want a branded, reliable hose setup for tank coupling.
- Key Benefits: 3/8″ diameter hose, brass fittings, built for durability.
- Pros: Trusted brand, strong hose material, leak-resistant.
- Cons: Slightly pricier than generic kits.
Final Verdict: Reliable brand-name option for smaller coupling projects. Check Price
Comparison Table
| Product | Type | Best For | Pros | Price |
|---|---|---|---|---|
| Milton S-682 Kit | Manifold Kit | General users | Easy install, rugged | Check Price |
| WYNNsky Coupler Set | Brass Fittings | Budget setups | Cheap, durable | See Price |
| RapidAir MaxLine | Piping Kit | Shops | Professional-grade | Check Price |
| Campbell Hausfeld 11-Gal | Aux Tank | DIY storage | Portable, strong | View Price |
| Hromee Kit | Accessory Kit | Starters | Complete set | See Price |
| DeWalt Hose Kit | Hose + Fittings | Small projects | Brand reliability | Check Price |
Frequently Asked Questions
Does coupling two tanks increase SCFM?
No. SCFM depends on the pump. Adding a tank increases storage capacity, giving longer tool run times before the compressor cycles on again.
Is it safe to connect two tanks?
Yes, as long as both tanks are rated for the same pressure, have relief valves, and you use proper fittings. Never exceed the lowest tank’s PSI rating.
Do both tanks need a drain valve?
Yes. Each tank should be drained daily to prevent rust and water buildup.
Should I buy a second tank or a bigger compressor?
If your tools need more SCFM than your compressor can deliver, you’ll eventually need a bigger compressor. If you just need more run time, a second tank is cheaper and effective.
Can I use a hose to connect two tanks?
Yes. A reinforced 3/8″ or 1/2″ hose with brass fittings is commonly used to couple portable tanks together.
Conclusion
Coupling two air tanks together is an affordable, effective way to extend run time and reduce wear on your compressor. While it doesn’t increase SCFM, it does make your compressor much more practical for demanding tools.
For most users, the Milton S-682 Manifold Kit is the easiest all-in-one solution. Budget buyers can start with the WYNNsky Brass Coupler Set, while shop owners should consider the RapidAir MaxLine Piping Kit for a professional setup.
Check today’s best air tank coupling kits and accessories here