On most ranges yes - the actuator head is a separate component that unscrews or unclips from the valve body.

Mechanically operated valves are usually built as a common body with an interchangeable operating head. The body contains the spool and ports; the head carries the plunger, roller, lever, button or whisker that actuates it.

That means a valve installed with a plain plunger can be converted to a roller lever if the machine member turns out to pass across rather than approach head-on, or to a one-way idle-return roller if the circuit needs to distinguish direction.

It is a genuinely useful flexibility during commissioning, when the required actuation frequently turns out to differ from what was assumed.

Check the range before relying on it: some compact valves have integral actuators and cannot be converted. And confirm the actuating force and travel of the new head, since they differ between types and the mounting position may need adjusting.

Because the valve must be positioned so the machine drives its actuator fully through the switching travel but not beyond its limit - and that is a fine setting.

Too far from the moving part and the actuator is not depressed far enough, so the valve switches unreliably or not at all. Too close and the part drives it past its mechanical limit, bending the plunger or breaking the mechanism.

A valve bolted rigidly in a fixed position has to be right first time and cannot be corrected when the machine is adjusted, when a component is replaced, or when wear shifts the geometry.

An adjustable bracket - slotted holes, a sliding clamp or a rail mount - lets the position be set at commissioning and re-set later.

Since mechanically actuated valves are mounted near moving parts and are the components most likely to be knocked out of position, that adjustability is worth specifying rather than treating as a refinement.

Fitting a valve where a different interface exists, and porting a valve so its connections are made to a plate rather than the body.

An adapter plate reconciles two mounting interfaces. Its main use is obsolescence: a valve range is superseded, an existing machine needs a replacement, and the current product has a different footprint or porting pattern. An adapter lets the new valve mount where the old one was without modifying the machine.

A sub-plate serves a different purpose - it carries the port connections so the valve can be removed without disturbing tubing, which turns a valve change into a two-screw job.

Both are worth considering at design stage rather than in an emergency. Specifying sub-plate mounting on valves likely to need replacement reduces downtime for the machine's whole life, and it costs very little at build time.

Record the interface designation in the machine documentation - it is what determines whether an adapter is even available.

Manual overrides in momentary and detented forms, plus replacements for broken ones.

A manual override lets a valve be operated without electrical power - essential for commissioning, fault-finding and freeing a machine that has stopped awkwardly.

Momentary overrides return when released, so the valve reverts to its commanded state. Detented overrides latch, holding the valve shifted until released deliberately.

The choice matters. A detented override left latched means that valve no longer responds to the control system, and the machine behaves inexplicably - a well-known source of confusing faults. Where the risk of one being left engaged is significant, momentary is safer.

Conversion kits allow one to be changed for the other, and replacement kits cover the common case of an override broken by being operated with a screwdriver.

Some kits also add a lockable or removable override for machines where unauthorised operation must be prevented.

With clips or brackets designed for the rail profile, which allows valves to be positioned and repositioned along a common mounting.

Rail mounting is convenient in control panels and on machine frames: a standard rail is fixed once, and components clip to it wherever they are needed, with the position adjustable by sliding.

For pneumatic valves this suits control panels where valves sit alongside electrical components, and machine installations where a group of valves must be positioned relative to the actuators they serve.

The considerations are mechanical: the rail and its fixings must be rigid enough that the valve does not move when tubing is connected or when the machine vibrates, and there must be clearance for fittings and tube bend radius behind the valve.

Where several valves are rail-mounted together, consider whether a manifold rail or a valve terminal would serve better - it consolidates the air supply as well as the mounting, which rail clips alone do not.

Access for maintenance, tube length to the actuator, exhaust clearance, and protection from the environment - in roughly that order of being forgotten.

Access is the one most often sacrificed at design stage and regretted afterwards. A valve tucked behind a fixed guard or under a machine bed saves space on the drawing and costs time at every intervention.

Tube length to the actuator determines response speed and air consumption, so valves should be as close to their cylinders as practical - which frequently conflicts with the desire to group them tidily in a panel.

Exhaust needs clearance: a silencer pressed against a panel is restricted, which slows the valve, and it is easy to do accidentally in a crowded installation.

And the environment - coolant, swarf, washdown, heat - should be considered where the valve will actually sit rather than where the machine looks clean in the drawing.

Sometimes, where interface dimensions are standardised - but it must be confirmed rather than assumed from appearance.

Certain valve mounting interfaces are standardised across the industry, so valves from different manufacturers conforming to the same interface will mount on the same sub-plate. That is genuinely useful for second-sourcing and for maintaining older machinery.

Outside those standards, mounting patterns, port positions and actuator threads are manufacturer-specific and often range-specific. A bracket that physically bolts up may position the ports wrongly or leave the actuator at the wrong height.

Actuator heads are almost never interchangeable between makes, since the thread and the plunger geometry are specific to the valve.

So record the interface designation where one applies, and otherwise treat mounting hardware as specific to the valve family. Keeping that information in the machine documentation is what makes a replacement straightforward years later.