Complete Guide to the Suttner ST-160 Single Foam Injector
Complete Guide to the Suttner ST-160 Foam Injector
The Suttner ST-160 Foam Injector is a professional-grade downstream injector designed to deliver maximum performance, reliability, and chemical draw efficiency in foam and wash systems. Whether you're running a commercial wash setup or a dedicated mobile detailing rig, this injector is the backbone of any quality foaming system that relies on downstream chemical injection.
In this complete guide, we’ll cover everything you need to know about the ST-160—from how it works, proper setup, compatibility, and maintenance to its advantages over other injectors on the market.
What Is the ST-160 Foam Injector?
The Suttner ST-160 is a high-precision chemical injector designed for downstream foam applications. That means it draws chemical into the water stream after the pressure washer pump, using the pressure differential created by a properly sized soap nozzle or foamer lance.
This injector is known for:
- Consistent draw rates
- Durable brass and stainless steel construction
- Reliable operation at higher pressures and flow rates
It's compatible with cold and hot water up to 180°F, making it versatile for year-round use in a wide range of wash environments.
Key Features
- Rated for pressures up to 4,000 PSI
- Compatible with flow rates between 2.0–5.0 GPM
- Draw rate: Approximately 10–20%, depending on nozzle sizing and backpressure
- Built-in metering adjustment knob for fine-tuning your soap-to-water ratio
- Stainless steel spring and ball for corrosion resistance
- Quick connect or threaded options available for easy integration
How to Set Up the ST-160
1. Install in a downstream position:
The ST-160 must be installed after your pressure washer pump, either directly at the pump outlet or somewhere in your high-pressure line using appropriate fittings.
2. Use with a foam cannon or foamer lance:
For the injector to activate and draw chemical, a low-pressure orifice must be used—such as a Chem-X Chrome Cannon 2.0, Freedom Foamer Lance, or a dedicated QC soap nozzle.
3. Connect the chemical supply line:
Insert the clear pickup tube into your soap container. The ST-160 comes with a barbed fitting for easy connection. Use weighted strainers or check valves to prevent backflow or contamination.
4. Adjust the metering knob:
Fine-tune the chemical ratio to your desired level using the built-in metering knob. Turning it clockwise reduces draw; counterclockwise increases draw.
Best Practices for Use
- Use with properly sized nozzles. If your soap nozzle’s orifice is too small, the injector won’t activate. Chem-X provides enlarged soap nozzles specifically for use with the ST-160.
- Avoid restricting the outlet. High backpressure prevents the injector from functioning. Always use foamers or lances designed for downstream setups.
- Rinse the injector after use. Run clean water through the system to prevent soap buildup or clogging.
Common Applications
The ST-160 is ideal for:
- Truck and trailer washing
- Agriculture and fleet cleaning
- Construction equipment washing
- Touchless car wash setups
- Mobile detailing rigs using downstream foam systems
Pair it with Chem-X soaps like Stars + Stripes, Old Glory, or Snake Oil for premium foam performance.
Maintenance Tips
- Inspect regularly for debris in the check valve or orifice
- Flush with clean water after each use, especially with high-viscosity soaps
- Replace internal parts like the spring, ball, or O-rings as needed—Suttner offers rebuild kits for easy service
ST-160 vs. ST-164: What’s the Difference?
The ST-160 is the classic high-performance injector—simple, durable, and effective.
The ST-164 is a dual-line metering version, allowing you to run two chemicals through a single injector body. It’s perfect if you frequently switch between soaps (like Stars and Stripes) without needing to change pickup tubes.
If you don’t need dual chemical functionality, the ST-160 is the go-to for reliability and simplicity.
Final Thoughts
The Suttner ST-160 Foam Injector is a staple component in professional wash setups. When paired with the right nozzle and premium Chem-X chemicals, it delivers unbeatable foam coverage, consistent performance, and long-term durability.
If you're looking for a no-fuss, high-output injector that just works—this is the one to build your system around.