Conbraco 27-401-01 Siphon Loop

The Conbraco 27-401-01 is a standard-setting 180-degree steam gauge siphon loop designed to protect sensitive instrumentation from the destructive effects of live steam. Constructed from 1/4-inch heavy-gauge seamless brass tubing, this pigtail siphon acts as a thermal barrier by trapping condensate within its loop. This "water seal" prevents high-temperature saturated steam from directly entering the Bourdon tube of your boiler pressure gauge or Pressuretrol controller, ensuring accurate pressure transmission while dissipating latent heat. With a service rating of 250 psig saturated steam and up to 400 psig at 100°F, this component is essential for maintaining the operational integrity of commercial steam systems. Its 5-5/8" overall length and 1/4" Male NPT connections provide a compact profile for tight mechanical room headers. Specifically engineered for vertical installations, the Apollo 27-401-01 prevents premature diaphragm failure and internal scaling, making it a mandatory HVAC replacement part for any high-pressure steam application requiring reliable steam gauge protection.

• Thermal Protection: Creates a reliable condensate trap that shields internal gauge components from extreme steam temperatures.
• Heavy-Duty Construction: Built from seamless brass to resist corrosion and stress cracking better than standard black iron alternatives.
• Pressure Surge Dampening: The 180-degree geometry helps buffer rapid pressure spikes and water hammer, stabilizing gauge needles for easier reading.
• Code Compliance: Meets standard requirements for non-ferrous siphons in many jurisdictions, reducing the risk of clogging from pipe scale.

Do I need to prime the siphon before installation?
Yes. For immediate protection, the loop should be filled with water prior to mounting the gauge. This ensures a liquid barrier is present the moment the steam header is pressurized.

Can this be used on horizontal pipe runs?
The 180-degree "pigtail" design is optimized for vertical orientation to ensure the condensate remains trapped in the bottom of the loop. For horizontal applications, a 90-degree coil siphon is typically preferred.

Why is my steam gauge reading zero despite the boiler being on?
Internal blockages from sediment or scale can occur within the 1/4" tubing over time. Technicians should regularly inspect and clear the siphon loop to ensure unobstructed pressure transmission to the controller or gauge.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.