Normally closed

The Normally closed section groups pneumatic components within the context of compressed-air systems in vehicles, machinery and workshops.

The full category path is All products in the shop/Hydraulics & Transmission/Pneumatics/Process control valves/Valves with external control/Normally closed. It shows where the category sits within the range and helps users select the correct product section.

Application and purpose

Parts in this group prepare, store, transmit or control compressed air. A single trade name may cover several designs, so compatibility must be confirmed from technical data rather than from an image alone.

Category scope

This is a detailed catalogue category. Variants may differ by one dimension, mounting side, connection type, material or a machine production cut-off date.

How to select the correct product

Start by identifying the machine, equipment or assembly. Then compare the features that most often determine compatibility:

• working pressure
• tube or hose diameter
• thread and connection type
• flow rate and control method
• machine or equipment make, model and version
• catalogue number, OE number or manufacturer reference

Technical product data shows that several parameters may matter at the same time, depending on the part's function: dimensions, material, temperature range, pressure, flow, voltage, load rating or connection type. An OE or manufacturer reference is extremely useful, but it should still be checked against dimensions and equipment version.

If several versions exist for one model, record the production year, serial number, engine or gearbox code and the marking on the old part. A photograph of the mounting position may help, but it does not replace measurement and specification comparison.

Installation, operation and safety

Depressurise the system and secure moving parts before opening any connection. Maintain cleanliness, use compatible seals, then perform leak and function tests after assembly.

For safety-related parts, pressurised systems, electrical work and chemicals, manufacturer instructions, required competence and suitable protective equipment always take priority.

FAQ

How can product compatibility with the machine be checked?

Compare make, model, serial number or VIN, OE number, dimensions and all operating parameters. Where one model has several variants, also check the production date and assembly code.

Does a similar appearance confirm that the part will fit?

No. Similar parts may have different dimensions, threads, materials, operating ranges or mounting sides. Technical specifications should be the basis of the decision.

What should be checked after installation?

Check fixings, leakage, freedom of movement and operation of the relevant system. Testing should be carried out without load or under controlled conditions, in line with the manufacturer's instructions.