Trafag has expanded its Picostat mechanical pressure-switch line with three variants aimed at different pressure profiles, giving OEMs and plant engineers a more clearly segmented choice between bellows, membrane and piston sensing in the same compact platform. The move is aimed at applications where mechanical switching is still preferred for its simplicity, fixed behaviour and certification track record, particularly in marine, rail, engine and hydraulic systems.
The new spread is built around the PST4B 9B4, PST4M 9M4 and PST4K 9K4. The 9B4 uses a bellows element and is targeted at vacuum, low and medium-pressure duties, where repeatability and wide media-temperature tolerance matter. The 9M4 uses a membrane design for medium-to-high hydraulic pressure ranges and steadier load conditions, while the 9K4 moves to a piston arrangement for more pulsating, high-pressure circuits where shock loads and spikes are harder to avoid.
That division matters because many of the harshest installations do not fail on headline pressure alone. They fail on vibration, over-pressure events, temperature swings, and the practical realities of mounting a switch in cramped machinery spaces. Trafag is pitching the three models as a way to match the sensing principle more closely to the duty cycle, while keeping the rest of the integration package broadly familiar across the range.
Across the three models, the Picostat architecture retains a floating change-over contact, EN 175301-803-A plug connection, IP65 protection, and resistance to vibration and shock. The housings and sensor materials also vary by model, allowing specifiers to balance corrosion resistance, sealing choice and media compatibility without moving away from the same overall form factor. For shipyards, rolling stock builders and hydraulic equipment manufacturers, that consistency can simplify panel layouts, spares policy and qualification work across multiple machine types.
The marine angle remains particularly important. Trafag’s Picostat switches sit inside a product family long established in shipbuilding and railway applications, and the 9B4, 9M4 and 9K4 are offered with a set of marine approvals alongside EN 60730 conformity for safety-related use cases. In practice, that keeps mechanical pressure switching relevant in a market increasingly crowded with electronic sensing, especially where ruggedness, long service life and straightforward control-circuit integration still carry more weight than added software layers.
