The gasket primarily determines the medium and temperature limits of the coupling. The gasket grade is marked with a colour stripe. Always make sure the selected gasket is suitable for the application, and never expose a gasket to temperatures above its rating. Lede gaskets are designed to standards such as ASTM D2000, AWWA C606, NSF 61 and IAPMO.
| Grade | Colour stripe | Use | Max. temperature |
|---|---|---|---|
| EPDM (E) | Green | Cold and hot water, chlorinated and sea water, dilute acids, oil-free air. Not suitable for petroleum oil and solvents. | +110 °C |
| Nitrile (T) | Orange | Petroleum and mineral oils, vegetable oils, aromatic hydrocarbons | +82 °C |
| White nitrile (A) | White | Oily food, pharmaceutical and cosmetic production (FDA-compliant ingredients) | +82 °C |
| Silicone (L) | Red | Dry hot air free of hydrocarbons, some high-temperature chemicals. Can also be used in dry fire protection systems. | +177 °C |
| Fluoroelastomer (O) | Blue | Oxidizing acids, petroleum oils, halogenated hydrocarbons, hydraulic fluids | +149 °C |
For lower temperature limits and details see the Lede catalogue.
Vacuum
Standard gaskets seal well up to 10 inHg (254 mmHg) vacuum, which can occur when the system is drained. Above this, with continuous vacuum, rigid couplings with GapSeal or end-protected (EP) gaskets are recommended.
Dry-pipe and freezer applications
GapSeal Grade E gasket is recommended. It closes the gap between pipe ends or in the gasket cavity and prevents residual liquid from entering the cavity and freezing. Do not use ordinary lubricant; use a petroleum-free, silicone-based lubricant. Rigid couplings are preferred in these applications; reducing couplings are not recommended.
Materials
Standard coupling housings are ASTM A536 Gr. 65-45-12 ductile iron (tensile strength 448 MPa, yield strength 310 MPa, elongation 12%). For applications requiring boiler code compliance, ASTM A395 Gr. 60-40-18 is also available. Stainless steel options: CF8 (304), CF8M (316), CF3M (316L), optionally 2205 duplex and 2507 super duplex. Bolts and nuts are oval-neck track bolts (UNC or ISO metric); stainless versions have a molybdenum disulphide coating to prevent galling.
For quotes and technical support, contact us: +90 216 327 85 05, info@teknoyangin.com.tr.