Prevent the pigtail from hanging vertically

To prevent a pigtail siphon from hanging vertically, proper support and installation techniques must be used to maintain its looped shape and ensure effective condensate protection.Proper Support for Pigtail Siphons

Pigtail siphons, also known as lyre-type siphons, are designed to protect pressure gauges from high temperatures and pressure surges by forming a liquid seal in the loop . If the pigtail hangs vertically without support, it can compromise the liquid seal, reduce heat dissipation, and potentially allow direct contact of hot media with the gauge . To prevent this:

• Use rigid or guided supports: Attach the pigtail to nearby structural elements using clamps, cleats, or brackets that hold the loop in position without restricting its intended flexibility .
• Install near the gauge: Position the siphon so that the loop is supported close to the pressure gauge, reducing vertical sag and maintaining the correct orientation .
• Avoid unsupported long vertical runs: Long vertical sections can cause uneven thermal expansion and stress. Break the vertical run into shorter supported segments if necessary .

Installation Tips

• Pre-fill the siphon: Before operation, fill the pigtail with water or another suitable liquid to establish the condensate seal .
• Maintain loop orientation: Ensure the loop is horizontal or slightly inclined rather than fully vertical to allow condensate accumulation and proper heat dissipation .
• Select appropriate materials and thickness: Use pipe materials and wall thickness rated for the system's pressure and temperature to prevent deformation under load .

Optional Enhancements

• Use spring hangers or struts: For systems with vibration or thermal movement, spring hangers or struts can support the pigtail while allowing minor movement without vertical sag .
• Bleed valves: Installing a needle valve with a bleed near the gauge can help remove trapped air and maintain smooth flow through the siphon . By combining proper support, careful orientation, and pre-filling, a pigtail siphon can maintain its looped shape, ensuring effective protection of the pressure gauge and preventing vertical hanging that could compromise its function .