Teflon Hose Installation Guidelines

Prior to Installation

  1. Always examine the hose for any obvious damage. IF THE HOSE IS DAMAGED, DO NOT USE. Some examples of damage may include slices to the cover, kinks or crushing of the hose, which can reduce life and pressure rating.
  2. Review your application to ensure the proper selection of hose has been made by examining materials, pressures, chemical compatibility, temperature and application environment.
  3. Hose movement should be restricted to a SINGLE PLANE (DRAWING B) to minimize the resultant twisting (torque). Note: The flexing plane should also be the plane in which bending occurs. Excessive bending will induce stress fatigue (DRAWING A).
  4. Axial movement should be eliminated. The hose should not be stretched or compressed along its longitudinal axis when installed in-line (DRAWING C).

Installation

  • NEVER USE HOSE BELOW MINIMUM BEND RADIUS - (DRAWING D). Bend radii (measured to insideradius hose) are given for individual products and sizes (consult SPS for specific data). These values represent the minimum bend radius to which the hose can be properly installed. If these values are not maintained, the hose can fail prematurely.
  • DO NOT ALLOW SEVERE BENDS. Severe bends can cause kinking in a hose or overstressing of the assembly/material, resulting in damage and ultimate failure. If severe bends cannot be avoided, use elbows designed to accommodate the direction change (DRAWING E).
  • DO NOT TWIST (TORQUE) ASSEMBLY ALONG CENTERLINE DURING INSTALLATION. The likelihood of leakage/failure increases for hoses that are twisted (torque) during assembly. The proper use of floating flanges and swivel type fittings can eliminate improper twisting.

Service Life Factors

The actual service life of the hose assembly is strongly affected by its environment. Some of the factors that may influence service life include:

  • Fatigue (including)
    • High-cyclic
    • Flexure
    • Pulsation
  • Corrosion
    • General corrosion attack
    • Stress corrosion crackin
    • Intergranular corrosion
    • Pitting corrosion
    • Torsion
  • Vibration
  • Wear
  • Proper hose configuration should be used when hose may … be exposed to movements from attached piping (i.e., … thermal growth)

Correct and incorrect installation techniques for hoses and tubing.

Instructions for Hose Assemblies with "Flare-Thru" Fluoropolymer Flanged end Fittings

Flange Covers should not be removed until hose is ready to be bolted into position. Flange covers should be replaced immediately after disconnecting hose to protect sealing surfaces.

Gaskets are not required when hose assemblies are connected to a sealing surface of like fluoropolymer (i.e.: PTFE. PFA, FEP) however, gaskets must he used when connecting flare-thru hose to a surface such as metal, glass, carbon, reinforced plastic, etc.

Bolts should be tightened using proper bolt torque's. The table below gives torque values for lined hoses using Class 150 flanges .

Nominal Hose Sizes

Teflon Products Installation Notes
Fig 1.6 - Torque (ft.-lbs.)

Teflon Products Installation Notes
Fig 1.7 - Bolt Torue Sequence

Torque can he approximated by gripping a wrench with one hand and applying a force of about 50 pounds. The hand should be placed about the distance equal to the bolt circle diameter from the bolt. For accurate tightening, a torque wrench is recommended. If a flange leak occurs on one side of a properly torque flange. the bolts should not be over torque. Instead loosen the bolts on the non-leaking side the same amount as you tighten the bolts on the leaking side. Any welding near the hose should be done in a manner to protect the fluoropolymer liners from being overheated and distorted. Hose should he disconnected only after hose has reached ambient temperature.

Notice

Due to our continuous effort to improve our products, the information contained in this document is subject to change without notice. We assume no obligations for liability for any advice furnished by it or for results obtained with respect to those products. All such advice is given and accepted at the buyers risk. Final determination of suitability of any information or product for the use to be contemplated is the sole responsibility of the user. This document contains proprietary information that is protected by copyright and may not be reproduced in any form without written consent of SPS.