Pneumatic and electro- pneumatic valve positioner

Product catalog summary

Overview: The document provides technical specifications and installation guidelines for the SOMAS valve positioners, specifically the SP405 pneumatic and SPE405 electro-pneumatic models. These positioners are designed for rotary motion up to 90° and can be adapted for linear motion actuators.

Specifications:

SP405: Operates with a pneumatic input signal of 20-100 kPa (0.2-1 bar or 3-15 psi). It features high accuracy, high capacity, and clear visual position indication.
SPE405: Incorporates an I/P-converter for an electric input signal of 4-20 mA. It shares similar features with the SP405, including high accuracy and capacity.

Functionality:

SP405: Utilizes a diaphragm and balance arm to control a pilot valve, adjusting the position based on input signal changes.
SPE405: Adds an I/P-converter to the pneumatic system, using a magnetic force to adjust the flapper and nozzle, affecting diaphragm pressure.

Installation: The positioners are designed for easy mounting on actuators using a standard mounting block. Adjustments for range and zero-point are accessible externally.

Material Specifications: The housing is made of aluminium with Duasolid paint, while other components like the balance arm and cam disc are stainless steel.

Technical Specifications:

Control signals: SP405 (20-100 kPa), SPE405 (4-20 mA).
Air consumption: SP405 (max 10 Nl/min), SPE405 (max 15 Nl/min).
Air capacity: Approximately 450 Nl/min for both models.
Supply pressure: 4-8 bar.
Ambient temperature range: -40° to +100° C.
Protection class: Equivalent to IP65.

Additional Information: The document includes dimensions and notes that SOMAS reserves the right to make improvements without prior notice.

Catalog excerpts

Pneumatic and electro- pneumatic valve positioner-1

Datasheet Valve positioner Type SP405 Type SPE405 • High accuracy • High capacity • Clear visual position indication • Good resistance to vibration • Easy setting Pneumatic Electro-pneumatic The SOMAS pneumatic positioner type SP405 (20 – 100 kPa) and the electro-pneumatic type SPE405 (4 – 20 mA) are developed to meet the demands from the process industry. The SOMAS positioners are intended for a rotary motion up to 90°. They are developed for quarter turn actuators and valves but can easily be adapted for actuators with a linear motion. A number of different cam discs are available to cover various signal ranges, angles of rotation and valve characteristics. All cams discs are for a rotary motion of 60°-90°. Other types of cam discs on request.

Open the catalog to page 1

Pneumatic and electro- pneumatic valve positioner-2

Function SP405 (Pneumatic type) A pneumatic input signal (20-100 kPa bar*) acts on a diaphragm (41) and via the balance arm (46) the pilot valve (40) is controlled. When the input signal increases, the pilot valve distributes supply air to one side of the piston while the other side is vented. The cam disc (32), which is adjustable to the shaft (26), transmits the rotary motion of the actuator to the feed-back arm (35). The feed-back arm acts on the feed-back spring (53) and when there is a balance between the force from the diaphragm and the force from the feed-back spring, a new balanced position...

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Pneumatic and electro- pneumatic valve positioner-3

Installation Rotary motion The transmission of the rotary motion between actuator and positioner is of a new design. No extra parts are needed for mounting the positioner SP/SPE405 on the actuator type A. The setting of range is done with the adjustment screw (7). The zero-point can easily be adjusted from the outside by means of a screwdriver on screw (50). Mounting on a standard actuator To reach the zero-point screw the cover (31) has to be opened (see the manual Mi-805). A mounting block is used as a standard solution to mount the positioner to the actuator. When the mounting block is used...

Open the catalog to page 3