Copper Nickel Products
Engineering Polymers
Precision Shims
Flange GuardsPTFE vs PP Flange Guards: Which Spray Shield Do You Need?
Short answer: use PTFE flange guards on hot lines, steam, hydrocarbons and pressurised service: our PTFE guards are rated up to about 240 °C and 120 bar (1650 psi) and are fire retardant. Use PP box-type flange guards for acids, alkalis and corrosive chemicals at moderate temperature, up to about 90 °C. Their rigid, semi-transparent body lets operators see a leak without removing the guard.
Comparison
| Feature | PTFE flange guard | PP box-type flange guard |
|---|---|---|
| Construction | Layers of PTFE-coated fibreglass cloth, Kevlar® stitched | Rigid virgin polypropylene sheet, box shape |
| Max. temperature | about 240 °C | about 90 °C |
| Pressure | up to about 120 bar (1650 psi) | Low-pressure spray protection |
| Chemical resistance | Excellent, almost all chemicals | Very good for acids, alkalis and salts |
| Leak detection | Litmus (pH) patch changes colour | See-through body (clear or milky white) |
| UV / outdoor | UV resistant | Very high UV resistance |
| Fits | Flanges, valves, couplings, elbows, tees, unions | Flanges about 1″ to 12″ |
Why flange guards are fitted
A gasket failure on a pressurised line can spray hot or corrosive fluid several metres. A flange guard contains the spray, protects people and nearby equipment, and shows where the leak is so it can be fixed before it gets worse. They are common on acid, caustic, hydrocarbon and steam lines in refineries, chemical plants, water treatment and desalination.
Choosing quickly
- Above about 90 °C, steam, or hydrocarbon service: PTFE
- Acid or caustic dosing lines at ambient temperature where you want to see the joint: PP
- Irregular shapes (valves, elbows, tees): PTFE, which is made to fit
Related guide: PTFE grade selection.
Need a price or stock check? Send the grade, size and quantity to sales@saifexindustries.com, WhatsApp +971 58 535 2330, or request a formal quote. See our PTFE flange guards.
Or see PP box-type flange guards.
Frequently asked questions
What is a flange guard?
A flange guard (spray shield) is a cover fitted around a flange or valve joint that contains any spray if the gasket leaks, protecting people and equipment.
What temperature can a PTFE flange guard take?
Our PTFE flange guards are rated up to about 240 °C.
When should I use a PP flange guard?
For acids, alkalis and corrosive chemicals at up to about 90 °C, especially where you want to see the joint through the guard.
How do flange guards show a leak?
PTFE guards carry a litmus patch that changes colour on contact with acid or alkali. PP guards are semi-transparent so the leak can be seen.