Trafag's Picostat mechanical pressure switches for reliable and repeatable switching performance
Trafag, a manufacturer of high-accuracy measurement devices, has highlighted its Picostat range of mechanical pressure switches with three complementary models, the PST4B 9B4, PST4M 9M4 and PST4K 9K4, designed to provide reliable, repeatable switching performance in demanding shipbuilding, engine manufacturing, railway, machine tool and hydraulic applications. The Picostat model features a mechanical sensing principle that addresses specific pressure dynamics and media conditions
The PST4B 9B4 utilises a bellows measuring principle, providing a mechanically simple and robust sensing element with high durability and stable switching over time, suited to vacuum and low- to medium-pressure ranges from -0.6 to 3.4 bar to 4 to 40 bar. This design, in combination with high over-pressure capability up to 50 bar, repeatability of ±0.5% FS, fixed switching differentials and an adjustable switch-point range from 10 to 90% FS on request, enables precise, consistent switching where fine control and wide media temperature capability from -25 to 125°C, down to -40°C with specific sensor options, are essential.
The PST4M 9M4 is built around a membrane-measuring principle that provides reliable pressure sensing for hydraulic and other media across medium- to high-pressure ranges of 1 to 10 and 10 to 100 bar. This membrane design is suitable for applications where stable pressure levels and moderate dynamics dominate, combining repeatability of ±2.0% FS with fixed switching differentials tailored to each range and an adjustable switch-point window of 10 to 90% FS on request. With a media and ambient temperature range of 0 to +80°C and an anodised aluminium EN AW-6082 housing, the PST4M 9M4 provides a balance of robustness and accuracy for a variety of industrial and mobile hydraulic systems.
The PST4K 9K4 with a piston measuring principle using a 1.4035 piston and PTFE sealing is suitable for highly dynamic and high-pressure environments. This configuration is designed for high-pressure and pulsating hydraulic media, covering 1 to 10 bar and 40 to 400 bar, with high overpressure capability up to 600 bar, supporting long service life under severe pressure shocks and spikes. The PST4K 9K4 achieves repeatability of ±1.0% FS with fixed switching differentials matched to each range, and an adjustable switch-point range of 10 to 90% FS on request, while its temperature range of -25 to +125°C and ambient range of -25 to +85°C allow reliable operation in hot and cold process conditions.
All three Picostat switches share installation and connectivity advantages that simplify integration across diverse systems. An output signal via a floating change-over contact offers simple integration into existing control circuits without additional interface relays. A standardised EN 175301-803-A plug connection protection up to 95% relative humidity supports safe, reliable operation in industrial power environments, humid engine rooms, and coastal installations. Each model combines an IP65-protected housing with high vibration resistance up to 5g, shock resistance of 50g for 3ms and installation in any mounting position, ensuring dependable operation in challenging, space-constrained environments.
The Picostat portfolio further enhances versatility with several pressure connections and mounting accessories, including a flange with O-ring, a fixing set, a covering cap, and a lead seal, to simplify panel mounting and on-site installation. Depending on the model, users can choose among sensor options, including bronze bellows with aluminium or brass housings and stainless steel bellows for the 9B4; FKM membrane sensors with anodised aluminium housings for the 9M4; and piston sensors with PTFE sealing for the 9K4, aligning material selection with media and corrosion requirements.
Across the range, approvals and conformity with ABS, BV, CCS, DNV-GL, KRS, LR or LRS, NKK, where applicable, RINA, RMRS for the 9B4, and EN 60730-1/2-6 Type 2.B.H simplify acceptance in marina and safety-related applications, decreasing certification effort for shipbuilding and OEM projects. Combining targeted sensing mechanisms within a common, vibration-resistant Picostat platform enables engineers to select the optimal mechanical switch for their specific pressure dynamics while maintaining a consistent, proven interface across their installations.