281.491.2331 13839 West Bellfort Street Sugar Land, TX
281.491.2331 13839 West Bellfort Street Sugar Land, TX
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Since 1954
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Welker Jet

Where to Use

  • Flow Control
  • Pressure Control
ApplicationsFlow Control, Pressure Control

Groundbreaking Design, Unmatched Control

Invented in 1958 by Robert H. Welker, PE, the Welker Jet® is the only natural gas control valve designed by a natural gas engineer specifically to meet the needs of the natural gas industry. Even after more than 60 years, no other control valve can compare to the quiet, durable, and versatile Jet®.

Where low energy loss, accurate performance, high controllable capacity, and minimal noise are critical, the Jet® offers unmatched system control. Responding to a control signal, the direct-acting pneumatically operated diaphragm motor provides hydraulic pressure to the rubber inner valve, which radially expands or contracts to control flow or pressure. The clean flow path through the valve conserves energy and reduces noise and downstream turbulence.

Optimize transmission stations, regulating stations, city gate stations, power plants, cogeneration plants, and supply fuel gas skids with a Welker Jet®. Available in top entry, flanged, or insert styles up to 600 ANSI and in five sizes ranging from 1” to 8”, there is a Jet® suitable for your application.

Go With the Flow

Streamlined Flow Path

This high recovery valve wastes little energy, so your downstream flow quickly returns to good flowing conditions. Without energy-robbing obstacles to distort flow, gas passes cleanly through the Jet®. The developed flow profile on the outlet reduces turbulence and noise.

Welker Jet Design
Why the WelkerJet®?


To Infinity and Beyond

Infinite Rangeability

From full flow to no flow, precise regulation is possible across 100% of the valve’s control range. Whether you order a 1-inch or an 8-inch valve, full control is a standard feature of the Jet®. Even at low flow conditions, the Jet® performs accurately across all valve sizes—it cannot be oversized!

The Sound of Silence

Noise-Canceling Design

With an inherent noise level of approximately 90 dBA, the Jet® is naturally 10–30 dBA quieter than other control valves. The control element is centered in the valve body, creating a straight path for gas to follow. With nothing to impinge upon, gas flows evenly—and quietly—on through. Welker can customize an inline diffuser for your application for further noise reduction.

Remember the Future

High Controllable Capacity

You don’t need to size up the Jet® to achieve the desired level of controllable capacity. The streamlined flow path prevents capacity from being lost to turbulence and allows critical flow to be reached with only a 20% pressure differential. Design new stations around the same Jet®, knowing it will accurately control initial low flow ranges and future high loads. Restrict controllable capacity mechanically with a liner if necessary.

Filling the Gaps

Positive Shutoff

Weld slag. Debris. Seat damage. Inner valve wear. Nothing can stop the Jet® from providing bubble-tight shutoff in the closed position. The resilient rubber inner valve expands to seal off around foreign objects, form into gaps in the seat, and fill in any voids in itself. Positive shutoff continues even in the presence of considerable damage.

Lightning Quick

Frictionless Hydraulic System

The Jet® gives you fast response time and stable control, no mechanical positioner required. The inner valve is linked to the pneumatic motor by a hydraulic system. As pneumatic pressure to the motor responds to changing conditions, hydraulic pressure quickly converts these changes into smooth inner valve motion.

Like a Dream

Easy Maintenance

Maintain Jet® valves of all sizes and styles with minimal personnel and downtime. One person can perform routine maintenance or annual inspection on a top entry valve in 1–2 hours, depending on size.

Double Duty

Pressure or Flow Control

A true control valve, the Jet® maintains outlet conditions regardless of inlet pressure changes. Confidently use the Jet® for pressure regulation control, back pressure control, or flow control. Install multiple Jet® valves in series for active/monitor configurations or in multiple side-by-side runs for smooth sequential control.

Master System
The Powers That Be

Control System Options

Harness the full potential of the Jet® with the right control system. Welker offers customizable conditioning systems to supply instrument-ready pneumatics to controllers, I/P converters, and pilot operators. Optional amplifying relays and volume boosters help your controller meet higher pneumatic pressure requirements and improve the response time of larger control valves.


WelkerJet® Control Valve
Materials of ConstructionA350 LF2 Carbon Steel, 1045 Carbon Steel, Aluminum 7075-T6 Bar, Buna, Proprietary Nitrile (Inner Valve), PTFE
Valve Size1"
Pipeline ConnectionSize: 1", 2", 3", 4", 6", 8", 10", or 12"
Rating: 150, 300, or 600 ANSI
Flange Facing: RF or RTJ
Utility RequirementsHydraulic Supply for Inner Valve Control: Texaco Aircraft Hydraulic Oil 5606G

Pneumatic Supply for Motor Actuation: Maximum 100 psig
OperationDiaphragm Motor
Operating Pressure150 ANSI Carbon Steel: 285 psig @ -20 °F to 100 °F
300 ANSI Carbon Steel: 740 psig @ -20 °F to 100 °F

600 ANSI Carbon Steel: 1440 psig @ -20 °F to 100 °F