Assembly Instruction

Assembly and Operational Safety Instruction


Assembly work should only be carried out by properly qualified personnel (DIN EN 1591-4).
Note:    Do not weld on lined pipes! The Fluoroplastic can be destroyed!

Protective Cover

All parts are provided with protective covers, for protecting the lining against dirt and mechanical damages by handling and storage and for holding down the flanges. The protective covers should only be removed immediately before assembly!


Additional seals between the PTFE sealing surfaces are not necessary, but may be necessary during the transition e.g. on metal, glass, ceramics, enamel, ETFE, PVDF, etc.


Flange fittings should be tightened evenly with a torque wrench, crosswise in several steps and in the end clockwise according to the following table.
Note:     The values for the tightening torques apply at room temperature!
Due to the flow characteristics of the lining, the fittings should be retightened after one day. After the first temperature cycle and commissioning, we recommend a repeated tightening of the screws. To avoid a deformation of the sealing surfaces by over tightening the screws during the assembly, the following torques are to be seen as a guideline (DIN):

The tightening torques are valid for lightly oiled/grease screws at normal temperature and are laid out for a slight flow of the lining in order to achieve an effective sealing. A further increase in the specified torques does not necessarily lead to a better sealing, but may lead to a deformation of the flare.

Equipotential bonding

Electrostatic charge can create an explosion hazard inside and outside the pipes. On the one hand, there is the risk of an electric shock when touched, and on the other hand there is the risk of ignition of a potentially present explosive atmosphere outside the pipeline.
Note:    Avoiding electrostatic charging is prescribed by the system operator for the respective protection area.

Conductive lining

To avoid charging, we recommend designing the pipeline to be electrically conductive or electrically dissipative. By grounding the system with e.g. lock washers, earthing bolts, sleeves and brackets the risk of discharge to the medium can be prevented.
Note: Lock washers are not suitable for repeated installation and removal (wear)

Splash guard

Many systems in the chemical industry are operated with aggressive media that must not get into the environment. Splash guards offer optimum protection in such cases. The flange connections of supply piping must therefore be protected against uncontrolled escaping medium.

Vent holes

With the exception of blind flanges, reducing flanges and G shaped spacers, all PTFE parts have vent holes with a diameter of approx. 3 mm. These are used for leak testing after production as well as leakage indication during operation. When installing, make sure that they are not blocked by paint or insulation. For environmental reasons or other regulations, these holes can be closed. In this case, the manufacturer excludes any warranty for damage resulting from this.

Vent hole sleeve/PTFE plugs

The stainless steel vent sleeve is attached to the ventilation hole. It enables the attachment of an extension in the event that the pipe is covered with insulation. This means that the ventilation can continue to be used. In addition, a threaded PTFE plug can be screwed into the vent sleeve.

Flange stopper

Flange stoppers can be installed behind a loose flange to prevent the loose flange from moving freely on the pipe or fitting.

Pressure-Temperature Resistance of Components according to DIN 2848 + 2874

The maximum thermal endurance amounts to 230°C. The allowable pressure in bar(g) above 120°C can be derived linearly from the values mentioned below.

Vacuum Resistance in bar(a) of PTFE-lined Pipes

The vacuum resistance of fittings is partially different. Please contact the manufacturer if necessary.


PTFE and PFA have proven as long-time corrosion protection.

With electrically conductive lining (black) it is recommended to check the existing conductivity of components regularly. In case of certain media, the conductivity can decrease by and by due to washing-out. Depending on various factors, permeation as well as absorption effects may occur. Permeation is the transport of media through the lining.

Due to all these effects, we recommend, for reasons of operational safety, a regular checking of all components.

All our components have TÜV component mark and correspond to the PED (Pressure Equipment Directive), the TRR 100 (German technical regulations for metallic piping systems) as well as to the WHG (German Water Management Act). If requested, we can also produce linings with FDA approval (Food and Drug Administration) according to CFR177.1550 (Code of Federal Regulations) as well as with approved pigments.

We assume no responsibility for the adequacy of the components delivered by us with respect to the planned utilization. Our components are not suitable for medical applications. For the assembly and the service of PTFE Expansion Joints, the corresponding instructions in our catalogue have to be observed. Please also take note of the corresponding operating pressure diagrams in the catalogue. The admissible operating pressure curves are downward sloping with increasing temperature. With standard wall thicknesses of the PTFE bellows, other diagrams than with thick-walled executions are valid.