Industrial 155SR Spring Return Ball Valve Actuator

Swagelok MS-155-SR is the 155 Series Pneumatic Spring-Return Actuator that delivers a precise 180° rotation to Swagelok ball valves and automatically returns to the closed position when air is removed. As a low‑pressure, single‑acting actuator, it is designed to mount with Swagelok ball valves and is part of Swagelok’s ball valve actuation options (MS-02-343). Key specifications include a unit weight of 12.5 lb (5.7 kg) and a cylinder displacement of 30.5 in³ (500 cm³) per actuation, enabling a definitive valve stroke in automated lines. The 155-series variant occupies the 180° actuation position in the MS-155 family; maximum operating pressure varies by model within the family, with 131/151 rated to 200 psi (13.7 bar) and 133/153 or 135/155 rated to 165 psi (11.3 bar) at 100°F (37°C) in standard service. This actuator is intended for industrial valve control applications where reliable spring return is required, such as process pipelines and automation loops that use Swagelok ball valves, providing a compact, maintenance-friendly solution with no continuous power draw once installed.