Pipe Couplings

General : This leaflet only contains pipe couplings and accessories which have been found after years of experience to be those generally required on the market, and are manufactured in bulk in three types according to DIN 2353 : very light = LL, light = L and heavy = S.

For special models, particularly couplings for higher pressures, we recommend that in the first instance the advice of our technical department or our agencies be obtained. Absolute reliability can only be guaranteed for HEP pipe couplings if HEP - parts are exclusively used, and if they are fitted in accordance with the unstructions (see page A 12 and A 13). Fitting instructions for workshops may be had on request.HEP - original parts are stamped with our trade mark.HEP

Standardisation : HEP - pipe couplings are supplied in accordance with DIN Standard specification 2353 (Summary). Screw-in couplings are deliverable with Whitworth pipe thread and metrical thread. Screw-in holes belonging to these couplings see page A 15 and A 16. Foreign standards can only be used in connection with screw-in threads. e.g. NPT - screw-in threads.

The Whitworth threads (R) indicated in this catalogue are BSP (T) threads, e.g. type GE 12-LR means a coupling with BSP parallel screw-in thread.

Material and Surface Protection : * HEP- pipe couplings of steel for steel pipes : - drawn and forged nuts : - cold-resp. warm-pressed (highest safety).
* HEP - pipe couplings of brass for copper pipes :- forged and drawn of seawater resistant quality Cu Zn 35 Ni (So MS 59)
* HEP - pipe couplings of stainless and acid-proof steel for stainless and acid-proof pipes : - drawn and forged.
* HEP - pipe couplings of heat-resistant steel : - on demand

Surface Protection :
* Pipe couplings of steel : (standard) for series L and S Exceptions see indications in the catalogue. bodies and nuts phosphated and oiled, cutting and locking rings cadmium-plated.
* Series LL : galvanic zinked, transparent bichromated
* On demand :
a) glavanic zinked, ransparent bichromated (short symbol : A 2K)
b) cadmium- plated and chromated (short symbol : B 2A)
C) galvanic zinked and yellow chromated (short symbol : A 2L)
Please and short symbol to the part No. f. i.: GE 25-SR-A 2K

Part No. :
The part Nos. mentioned in this catalogue refer to parts made of steel. They refer to complete parts.

A body as single part is marked with “X”, f.i. :
complete coupling GE 20-SR body without nut (m) and cutting and locking ring (d) X GE 20-SR

In case another material* is requested, please add to the part Nos. of the catalogue the following symbols :
for couplings made of Cu Zn 35 Ni ......................................................... Ms
for couplings made of stainless and acid-proof steel ....................... 1.4571
for couplings made of special materials ...................................... W. Nr.......
* (please note the indications on the different catalogue pages with regard to special materials!)

Pressures :
The pressures stated in the catalogue are nominal pressures, with a safety factor of at least 4:1. These figures may be used as the maximum working pressures under normal working conditions and temperatures up to 1200 C. In case of higher temperatures and in instances where there ate sudden increases pressure and high mechanical stress (vibrations etc.) we recommend the series (see under-mentioned fields of application).

The test pressure should be 50% higher than the working pressure (see DIN 2401 for fuller details). It is assumed that the pipes and equipment will be clamped position in such a way that the couplings will be free from any additional stresses loads and tensions.

Recommendations :
Pipe couplings : In general we recommend the use of HEP - pipe couplings for.
Series LL : for pneumatic systems, hydraulic runback systems propane, oil heating, vehicle industry, small-type refrigerating machines, synthetic piping etc.

Series L : as the series LL, but in case of higher mechanical stresses, pressure piping, etc.

Series S : heavy industry, shipbuilding, mining, chemical industry, big-type refrigerating machines, pressure piping etc.

Pipes : We recommend for our HEP - pipe couplings our HEP- seamless precision steel pipes, according to DIN 2391/C, made of material of special, quality, protective-gas / special-clean-annealed, free of scale (NBK), phosphated / oiled, with tightness test.

The pressures given in the table below for the minimum wall thickness stated, without any addition for corrosion, are based on a safety of 4 x.

Conversion Table :
1 psi = 0,0703 kp/cm21kp/cm2 = 14,223 psi 10C = 1,80 F 10F = 0,5550C

Unit-composed system :
Standard types (couplings, such as GE, W, SV, etc) and the unit- composed parts :
* ri - (screw - in thread reducing pieces)
* KOR (cone reductions)
* evGE (adjustable straight made stud bodies)
* evW, T, L, (adjustable W-, T-, L- bodies)
* mav-ev (adjustable bodies for Manometer connectiion)

* form a system, which in many cases allows a rational and compact installation. Besides that the application od this unit-composed system is economical, because a voluminious stock holding can be avoided.

Our unit-complsed system is based on the following combinations
1. evGE + basic type (f.i. W, T, K, RHD, etc) With this combination you can form an adjustable screw-in coupling.
2. KOR + basic type (all bodies with cones) Unit - composed part KOR enables reductions at the cone side.
3. ri + basic type (all types with R-screw -in-thread) With the help of the reducing pieces ri the screw-in thread can be adapted to the dimension of the screw-in hole.
4. evW- T-L + basic type (all types with cones) Adjustable W-T-,L- bodies can be assembled with the basic types as well as with the adjustable bodies among themselves, f.i. :
evW + Xge = EVW page C 14
evT + Xge = EVT page C 15
evL + Xge = EVL page C 16

In case of special materials, such as brass, stainless and acid- proof materials, only the combination evGE + basic type is deliverable.