Our high-pressure screws and fittings are made of martensitic stainless steel like 1.4542 (17-4 PH), 1.4548 (15-5 PH) or 1.4534 (13-8 Mo). These materials have a higher yield strength than the commonly used strain hardened austenitic steels. The higher yield strength of our fittings and valves does not only result in a higher bursting pressure, but also in a better load alternation resistance and better sealing.
For usage with hydrogen we use hydrogen resistant materials. For usage with oxygen we use specially cleaned components.
All fittings and valves are supplied with pressure screws and collards. We supply fittings for all common tube diameters.
Our high-pressure fittings are available in four versions:
- Imperial thread, 60° cone
- Imperial thread, 120° cone
- Metric thread, 60° cone
- Metric thread, 120° cone
The 60° cones are a worldwide standard. They seal pressures up to 4,000 bars for tube diameters up to 9/16” (14,3mm). Using 9/16” tubes frequent load alternations may cause problems.
The 120° cones have the following advantages:
- They seal better, especially at higher pressures and larger diameters.
- The cone is shorter and more stable.
- The tendency of the 60° cone to crack due to the wedge effect of the more acute angle is replaced by a stabilizing effect.
- The production is easier. Only about a third of the amount of material needs to be cut compared to a 60° cone.
- A single cone cutting knife can be used for all tube diameters.
- The sealing surface, and therefore the stress for the pressure screw, is about 30% smaller.
To make a screw connection, a tube must be provided with a cone and a thread. With a tube bending tool, the tube can be bent into the desired shape. Damaged cones can be reworked by means of a cone finishing tool. For details about the tools, see section Accessories.
The tube is provided with a Collar and a pressure screw and can be screwed without rotation into the counterpart. If stronger vibrations or pressure surges occur, a Vibro fitting should be used..
Our fitting assortment includes:
The notches on our screws distinguish between our metric and imperial ones. The metric ones have one notch and the imperial ones two. The inner geometry is identical to those of the larger American manufacturers, so that their pressure rings can be used. Our glands are made of stainless steel 1.4404.
Our collars, in contrast to those of our competitors, have hexagons instead of round outer surface. This facilitates the assembly and disassembly of the collars by using a wrench. Our collars are interchangeable with almost all common high-pressure fittings and are made of 1.4404.
Elbows allow a cable routing of 90°. These are especially good in limited space conditions. Elbows with two identical connections are available in all common high-pressure connection sizes. Special versions with different connections or for different pressure ranges on request. In general, we offer elbows with right- and/or left-hand thread.
Vibrations, frequent load changes and movements of the tube, e.g. with tube spirals, can cause damaged sealing cones and seats and tear the threads of the tubes and their end. This does not happen with Vibrotight-fittings. We consider the separation of collar and clamp ring to be more efficient than sealing rings that are placed behind the collars, because the two components have to be tightened with different torque.
Our short-connections allow a compact, stable connection of two high-pressure components. One of the components should have a left-hand thread. If both parts have right-hand threads, the version with a “right-left-adapter” is used.
A tube inside the short connection is loosely placed and does not rotate while tightening. The short-connection is screwed onto the pipes the same way at both sides und pulls them together. A commonly committed mistake is that the pressure screw is screwed in completely on one side and therefore cannot connect both components properly.
Normally the bulkhead is the connection between system and environment. Our construction allows a strong bulkhead with minimal effort. We normally supply three 1mm discs for assembly. Depending on the wall thickness (1, 2 or 3mm) different numbers of discs are needed. Bulkheads for other wall thicknesses, e.g. polycarbonate walls, available on request. Our bulkheads are made of 1.4542 (17-4 PH).
Bursting discs are overpressure safety devices which can be used for almost all pressures in our range. The advantages are a relatively low price, a small size and a response without delay.
The disadvantages compared to pressure relief valves are that the burst pressure must be at least 30% above the operating pressure. For systems subject to acceptance, the permissible operating pressure must correspond to the bursting pressure of the system. This entails considerable additional costs. A new bursting disc must be used after each response. Even at normal operating pressure, the bursting discs can burst after some time due to fatigue. We have therefore endeavoured to manufacture pressure relief valves with costs in the range of bursting disc safety devices.
Choosing the right filter requires expertise. We offer filters for every pressure level and nominal diameter of our range. We generally do not use sintered metal filters as they do more harm than good. The selection of the filter depends on the following criteria:
- Operating pressure
- Throughput l/min.
- Expected contamination of the fluid
- Sensitivity of products to contamination
- Is a contamination indicator required?
- Is a pre-filter required?
Since one filter element usually does not remove all dirt particles, we like to insert two filter elements in series, often also in one housing.
Another common problem is that a possibly dirty part is pressurized with a clean fluid and therefore only the return flow is contaminated. In this case we offer filters with built-in check valves.