Flame Resistor
Product Model: ZD-FA05 (Pipe-Rack / Atmospheric Type)
Type: Atmospheric / Velocity-type (often End-of-Line)
Material: Housing: Cast Aluminum or Ductile Iron with corrosion-resistant coating. Element: Stainless Steel Matrix.
Key Feature: Compact, lightweight design specifically for installation at the open end of atmospheric vent pipes on pipe racks, relieving devices, or equipment skids.
Certifications: FM, UL, ATEX. Compliant with relevant venting standards.
Typical Use: Terminating atmospheric vent lines from pressure relief valves, pump seals, compressor vents, and instrument vent headers in petrochemical plants and refineries.
Overview
Throughout process plants, numerous small vent lines discharge flammable vapors to a safe location (typically a pipe rack leading to atmosphere). These open ends are potential ingress points for flame. The Pipe-Rack Flame Arrester is a compact, economical device designed specifically for this application. It is installed at the termination of these vent lines to prevent a fire on the pipe rack from traveling back into the connected equipment or the vent header system. Its design prioritizes low weight, ease of installation, and effective protection for these numerous, small-diameter vent points.
Features & Benefits
Lightweight & Compact: Easy to install at the end of vent pipes without requiring heavy support.
Cost-Effective Protection: Provides essential flashback protection for multiple vent points at a manageable cost.
Low Maintenance: Simple design with robust elements suitable for typical vent stream compositions (often air with trace hydrocarbons).
Variety of Connections: Available with threaded (NPT, BSP) or flanged connections to match common vent line sizes.
Weather Resistant: Materials and coatings selected for outdoor pipe-rack service.
How It Works
It operates as a velocity-type or matrix-type arrester. The element provides a barrier of narrow flow passages. If a flame approaches the vent opening from outside, it is quenched as it attempts to pass through the element due to heat loss to the metal walls. It also protects against flames that might stabilize at the pipe tip during venting of rich mixtures.
Specifications (Descriptive)
Common inlet sizes: ½", ¾", 1", 1½", 2" NPT or flanged. Body materials are often cast aluminum (Al-Si12) for lightness and corrosion resistance or coated ductile iron. The element is stainless steel. It is typically rated for Group IIA gases (e.g., Propane, Butane) as standard, with Group IIB available. It is designed for atmospheric discharge conditions (very low backpressure). Options include bird screens and rain caps.
Q&A
Q: Do I need one on every small vent line?
A: A hazard assessment should determine this. Typically, any vent line discharging a flammable mixture to a location where an ignition source could be present (like a pipe rack) should be protected. This is a common requirement in refinery and chemical plant specifications.
Q: Can it get plugged by ice or hydrate formation?
A: Yes, if the vent stream contains moisture that can freeze. For such services, heat tracing or a specially designed arrester with anti-icing features may be necessary. Regular inspection is key.
Q: What if the vent stream contains liquids or heavy condensate?
A: Liquid carryover can foul and eventually plug the element. A knock-out pot or drip leg should be installed upstream of the arrester to separate liquids. The arrester should be installed vertically with the element at the top to drain any condensate back.
Q: How do I inspect it?
A: Visual external inspection for damage or blockage. The element can usually be removed by unthreading the end cap (if designed for service) for internal inspection and cleaning.
About ZD Safety
We understand that plant-wide safety is built on protecting countless small points of vulnerability. Our pipe-rack flame arresters offer a practical, reliable solution to secure these atmospheric vents, contributing to the overall fire safety integrity of your facility.
