SILICONE FAQ’S
OIL AND SILICONE HOSE
Q: Am I able to use petroleum products (oil, fuel, transmission fluid, etc…) with silicone hose?
A: No, Flexfab does not recommend using silicone hose to convey oil, fuel, or other petroleum based products. The effects of these products
are very detrimental and will lead to hose failures. Failures that may occur are: hose leaks at connections and through the hose body (permeation).
Pictured below is the Flexfab 5526 series with hydraulic oil being conveyed through the hose.
The first signs of petroleum degradation in silicone are hose swelling and discoloration. The hose will also show signs of oil
permeating through the hose wall. If the hose is continued to be used under these conditions, this will lead to hose failures and downtime
of equipment.
Q: What if petroleum products were to “splash” onto the silicone hose in normal operation?
A: There are instances under normal operating conditions where oil will come into contact with silicone, by means of “splash”
conditions. In these cases, silicone will be able resist oil splash, with very little to no effect.
FOR REFERENCE ONLY
High-Performance Hoses, Ducts and Connectors
DISTRIBUTOR
STEAM AND SILICONE HOSE
Q: Is it ok to use silicone hose in a pressurized steam application?
A: Silicone has excellent resistance to boiling water, but resistance to steam can vary depending on the grade of silicone.
The table below is for general reference of the reversion of silicone in a pressurized steam application:
Temperature
Steam Pressure (PSI)
Steam Resistance
120°C (248°F)
130°C (266°F)
14
25
6 months
2-3 months
140°C (284°F)
38
6 weeks
Silicone rubber does not have any reversion within 6 months, soaked in 248°F steam. After 6 months; however, Silicone rubber may start
degrading (reversion-softening/turning into liquid polymer) slowly. If the tester runs constantly, the reversion of the silicone
polymer may occur after 1 or 2 years in service.
Pictured below is the internal effect of silicone hose being used in a pressurized steam application. The 5508 series coolant hose shows signs
of pitting, where the silicone has reverted to a liquid polymer.
Old Hose
New Hose
BARBED FITTINGS AND SILICONE HOSE
Q: Is it ok to use barbed fittings with silicone hose?
A: No, barbed fittings will cut into the silicone hose creating leak paths to the fabric reinforcement.
Pictured on the left is the internal effect on the hose, when barbed fittings are used. The barbed fitting punctured the internal liner of the 5526
series heater hose, creating a leak path for coolant.
Once the leak path is created, coolant is now able to access the
fabric reinforcement. With pressure build up, the coolant will force
the outer layer to burst (separate) from the fabric reinforcement.
To prevent leak paths and downtime of equipment, Flexfab recommends
using beaded fittings only. Beaded fittings have rounded edges, and
will not cut into the silicone. The picture above illustrates the external
effect of a blown hose where barbed fittings were used.
FOR REFERENCE ONLY
Phone: 888-353-9323 Fax: 888-353-9344 Email: [email protected] www.flexfab.com
UNLINED CLAMPS AND SILICONE HOSE
Q: Is it ok to use unlined clamps to secure silicone hose to a fitting?
A: Flexfab does not recommend using unlined clamps to secure silicone hose to a fitting.
Unlined clamps are not suitable for use with silicone, as the band notches are exposed. Using a lined clamp will prevent the hose surface
from extruding or shearing through the band notches.
Pictured below are the preliminary effects of using unlined clamps on Flexfab silicone hose. The hose exterior will extrude and shear as the
clamp load is tightened. If used under these conditions, there is a possibility of the hose blowing off of the end
fitting. This is due to the lessened clamp load as the clamp cuts into the silicone.
Flexfab utilizes all lined clamps available for sale to our distributors.
Pictured below are examples of approved clamps for use on Flexfab Silicone Hose:
2582 Series Lined Worm Gear Clamps: Coolant hose and Heater hose applications.
2584 Series Constant Tension Clamps: Coolant Hose, Heater Hose, and Charge Air Connectors.
2588 Series Spring Loaded T-Bolt Clamps: Charge Air Connectors.
2583 Series T-Bolt Clamps: Charge Air Connectors.
FOR REFERENCE ONLY
Flexfab GR 5333 33rd St. SE Grand Rapids, MI 49512
CUSTOM SILICONE HOSE QUOTE
Q: Can Flexfab manufacture a custom designed part for my application?
A: Yes, Flexfab can manufacture custom designed products. These parts are subject to minimum order quantities and lead times.
For a quote on a custom made product, please provide the following information:
• Formal request sent by email or fax to: [email protected] or 888-353-9344
• Estimated annual usage:
• Drawing if available:
• Material Specifications:
• Inside Diameter of the hose:
• Overall Length of the hose:
• Cuff Lengths (If hose is wire reinforced):
• Color of the hose:
• Temperature Range:
• Pressure (both positive pressure and negative pressure):
• Application of the hose:
Q: Can Flexfab manufacture a custom design of an existing product?
A: Yes, Flexfab can manufacture a custom design of existing products. These parts are subject to minimum order quantities
and lead times.
For a quote on a custom made product of existing design, please provide the following information:
• Formal request sent by email or fax to: [email protected] or 888-353-9344
• Estimated annual usage:
• Flexfab Part Series:
• Inside Diameter of the hose:
• Overall Length of the hose:
• Cuff Lengths (If hose is wire reinforced):
*Please note: All custom hose quotes have a 10 day lead time from engineering.
Flexfab GR 5333 33rd St. SE, Grand Rapids, MI 49512, Phone: 888-353-9323, Fax: 888-353-9344, www.flexfab.com
All rights reserved. ©2015 Flexfab Horizons International, Inc. A member of the FHI ® family of companies.
Flexfab® does not assume any liability for errors or omissions. ZZZ-39850 – June, 2015