Product Overview

DEENPU Model AH Hydraulic Actuator is a robust, piston-type actuator specifically designed for mounting on reverse-acting gate valves in critical wellhead safety applications. Its fail-safe, fail-close design ensures that the valve automatically closes upon loss of hydraulic control pressure, providing a fundamental layer of well control protection without reliance on external power or operator intervention.

The actuator operates on a closed hydraulic system that is completely independent of well fluids and well pressure. Hydraulic pressure applied to the piston holds the valve in the open position during normal operation. If control pressure is lost for any reason — whether due to power failure, line rupture, or deliberate emergency shutdown — the actuator’s return spring drives the valve to the fully closed position, isolating the wellbore and preventing uncontrolled flow.

As an added safety feature, DEENPU AH actuators incorporate a metal-to-metal seal between the bonnet and the lower stem. In the event of a fire, if the primary stem packing is damaged by extreme heat, this metal-to-metal secondary seal maintains pressure containment, providing critical fire-safe performance. The actuator is commonly used as a secondary master valve and wing valve on Christmas trees, flow lines, and other wellhead equipment where automated fail-safe closure is essential.

How It Works

The DEENPU AH actuator uses a piston-and-spring mechanism to control gate valve position. During normal operation, hydraulic control pressure is applied to the piston through the closed hydraulic system. This pressure overcomes the spring force and holds the piston in the retracted position, which in turn holds the gate valve in the open position.

When hydraulic pressure is lost — either through a controlled system shutdown or an emergency situation — the compressed return spring pushes the piston back to its resting position. This mechanical spring force drives the gate valve closed through the stem connection. The design is inherently fail-safe because the spring force acts in the fail-safe direction without requiring any external power source.

Upon restoration of hydraulic control pressure, the actuator automatically re-opens the valve. This automatic reset capability is valuable for remote or unmanned wellhead installations. The upper spring retainer keeps the return spring safely contained during maintenance.

Key Features

Parts Breakdown

The DEENPU AH Hydraulic Actuator is designed with 13 modular components for reliable operation and efficient maintenance:

1. Upper Spring Retainer
2. Housing
3. Down Stop Shaft
4. Bonnet
5. Slab Gate
6. Body
7. Top Shaft
8. Piston
9. Downstop
10. Spring
11. Stem
12. Packing Retainer
13. Seat Assembly

Applications

Ordering Guide

Quality Control & Testing

Frequently Asked Questions