Proven Line Stop Actuators That Drive Safety and Performance
Line stop actuators are essential for isolating pressurized pipelines during live maintenance, valve installation, or emergency repairs. By enabling safe flow diversion through bypass systems, they help reduce downtime, maintain operational continuity, and support compliance with pipeline integrity standards.
The Propipe Line Stop ACTUATOR Series: Function, Safety, and Performance
The Propipe Actuator is a line stop system, available in manual (ACTUATOR SS MN) and hydraulic (ACTUATOR I–IV HYD) versions, designed for safe, controlled isolation of pressurized pipelines. Engineered for live interventions, it enables technicians to insert and retract line stop heads without disrupting flow—making it ideal for temporary shutdowns, bypass setups, and valve replacements.
How It Works:
• Mounted on a valve and fitting pre-installed on the pipeline.
• Drives the line stop head into the pipe, sealing the flow path.
• Once isolation is complete, bypass systems maintain flow while work is performed downstream.
• After operations, the head is retracted and the valve is closed to restore full service.
This actuator is essential for field crews and maintenance teams requiring dependable, compliant solutions for pipeline isolation under pressure. Ideal for reducing downtime, enabling safe modifications, and maintaining system integrity
Key Functions:
• Line Stop Deployment: Inserts a sealing head into live pipelines to isolate flow for maintenance or rerouting.
• Bypass Integration: Supports continuous service by enabling flow diversion through temporary bypass lines.
• High-Pressure Compatibility: Hydraulic models are rated to 1,480 psig (102 barg) at 180°F (82.2°C), for liquid or gas.
Key Benefits:
• Live Isolation Without Shutdown: Perform line stops on active systems without interrupting service.
• Supports Valve Replacement and System Modifications: Enables safe access for upgrades or repairs.
• Minimizes Operational Risk: Reduces exposure during critical interventions.
Explore the Manufacturing Journey of the Propipe Line Stop Actuator
This video offers an inside look at the precision engineering behind the Propipe Line Stop Actuator—built for high-pressure pipeline isolation in demanding field conditions. From raw CNC machining to meticulous assembly, each stage highlights the technical expertise and manufacturing discipline that define Propipe’s commitment to reliability and performance. Witness the transformation from component to fully integrated actuator, ready for deployment in live pipeline operations.
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Line Stop Actuator Models and Specifications
General Specifications: Actuator I–IV HYD
Actuators I, II, III and IV HYD share these ratings. Size range, dimensions, weight and model-specific ratings are listed under each model below.
| Mating Flanges | Special “O” ring flange |
|---|---|
| Max Working Pressure | 1,480 psig (102 barg) at 180°F (82.2°C) |
| Max Working Temperature | 250°F (121.2°C) at 800 psig (55.16 barg) |
| Product Groups | Liquid or gas |
ACTUATOR SS MN
The ACTUATOR SS MN is a manual line stop machine and stop plug setter engineered for safe, efficient isolation of pressurized pipelines. Designed for pipeline sizes from 4″ to 12″, this model offers straightforward manual operation—making it ideal for routine maintenance, emergency interventions, and field repairs. Its lightweight, portable design ensures ease of transport and setup in demanding environments.
Key Features:
- Manual Line Stop Capability: Enables technicians to isolate sections of active pipelines without full system shutdown.
- Stop Plug Deployment: Facilitates safe insertion and removal of stop plugs for temporary flow control.
- Compact and Portable: Weighs just 72 lb (33 kg), making it suitable for remote or confined job sites.
- Versatile Application: Compatible with both liquid and gas product groups across various industrial sectors.
Specifications:
| Capacity | 4″ – 12″ (SS 275-500 machine, max 363 psi (25 bar); SS plugs are set with the PCM-0204 completion machine) |
|---|---|
| Max Working Pressure | 490 psig (35 barg) at 180°F (82.2°C) |
| Max Working Temperature | 250°F (121.2°C) at 800 psig (55.16 barg) |
| Control Bar Reach | 48″ (1220 mm) |
| Weight | 72 lb (33 kg) |
| Product Groups | Liquid or Gas |
This actuator is a trusted solution for pipeline crews seeking reliable, compliant tools for live line isolation and flow control. Perfect for minimizing downtime and maintaining operational continuity under pressure.
ACTUATOR I HYD
Propipe ACTUATOR I HYD – Hydraulic Line Stop Actuator for 4″–12″ Pipelines
The Propipe ACTUATOR I HYD is a hydraulic line stop actuator for isolating pressurized pipelines from 4″ to 12″. It is used for live maintenance, emergency repairs and valve replacements without shutting the system down.
Core Functions
- Line Stop Operations: Deploys stop plugs into live pipelines to temporarily block flow
- Flow Isolation Without Shutdown: Enables safe maintenance and modifications while maintaining system pressure
- Bypass-Compatible: Supports rerouting of flow during isolation procedures
Actuator I HYD specifications (from the data sheet)
| Pipe sizes | 4″ to 12″ |
|---|---|
| Mating flanges | Special O-ring flange |
| Maximum working pressure | 1,480 psig (102 barg) at 82.2°C (180°F) |
| Maximum working temperature | 121.2°C (250°F) at 800 psig (55.16 barg) |
| Overall dimensions, retracted | 72 × 14 × 7.5 in (1829 × 360 × 185 mm) |
| Overall dimensions, extended | 136 × 14 × 7.5 in (3440 × 360 × 185 mm) |
| Weight | 297 lb (135 kg) |
| Product groups | Liquid or gas |
ACTUATOR II HYD
Propipe ACTUATOR II – Heavy-Duty Hydraulic Line Stop Actuator
The Propipe ACTUATOR II is a robust hydraulic line stop machine engineered for isolating large-diameter pipelines ranging from 14″ to 20″. Designed for high-pressure environments and demanding field conditions, this actuator enables safe, controlled isolation of live pipelines—allowing maintenance, repairs, or system modifications without interrupting flow.
Its extended reach and heavy-duty construction make it ideal for use in oil and gas transmission systems, petrochemical facilities, and industrial fluid networks. Whether deployed during planned maintenance or emergency interventions, the ACTUATOR II delivers reliable performance under pressure.
Core Functions
- Line Stop Operations: Inserts a stop plug into active pipelines to temporarily block flow
- Live System Isolation: Enables safe work without depressurizing the entire system
- Bypass Compatibility: Supports rerouting of flow during maintenance or upgrades
- Hydraulic Control: Ensures precision and safety in high-pressure applications
Key Benefits
- Built for large-diameter pipeline isolation
- Operates under extreme pressure and temperature conditions
- Compatible with liquid and gas media
- Ideal for critical infrastructure and high-risk environments
- Supports safe, efficient field operations with minimal downtime
Actuator II HYD specifications (from the data sheet)
| Pipe sizes | 14″ to 20″ |
|---|---|
| Mating flanges | Special O-ring flange |
| Maximum working pressure | 1,480 psig (102 barg) at 82.2°C (180°F) |
| Maximum working temperature | 121.2°C (250°F) at 800 psig (55.16 barg) |
| Control bar reach | 102″ (2642 mm) |
| Hydraulic oil capacity | 23.2 gal (88 litres) |
| Weight | 999 lb (453 kg) |
| Product groups | Liquid or gas |
ACTUATOR III HYD
Propipe ACTUATOR III HYD – Hydraulic Line Stop Actuator for 22″–34″ Pipelines
The Propipe ACTUATOR III HYD is a heavy-duty, hydraulically powered line stop actuator engineered for isolating pressurized pipelines ranging from 22″ to 34″. Equipped with a high-capacity hydraulic system, this actuator is built to handle substantial mechanical loads and pressures during live pipeline interventions.
Its extended stroke and rugged construction make it ideal for critical maintenance, emergency repairs, and flow control operations across oil, gas, water, and industrial fluid systems—without requiring full system shutdown.
Core Functions
- Hydraulic Line Stop Operations: Deploys stop plugs into live pipelines to temporarily block flow
• Live System Isolation: Enables safe maintenance and modifications while maintaining system pressure
• High-Load Actuation: Handles up to 78,570 lbf (349.5 kN) for demanding field conditions
• Extended Stroke Capability: 140″ stroke for deep plug setting in large-diameter pipelines
Key Benefits
• Hydraulic operation for high-force plug deployment
• Extended stroke for deep-set line stop applications
• Built for large-diameter, high-pressure pipeline isolation
• Supports safe, efficient maintenance without depressurization
Actuator III HYD specifications (from the data sheet)
| Pipe sizes | 22″ to 34″ |
|---|---|
| Cylinder | 8″ cylinder, 4″ rod, 140″ stroke |
| Mating flanges | Special O-ring flange |
| Maximum working pressure | 1,480 psig (102 barg) at 82.2°C (180°F) |
| Maximum working temperature | 121.2°C (250°F) at 800 psig (55.16 barg) |
| Hydraulic system MWP | 1,000 psig (68.95 barg) |
| Maximum mechanical load | 78,570 lbf (349.5 kN) |
| Overall dimensions, retracted | 177 × 24 × 20 in (4500 × 600 × 500 mm) |
| Overall dimensions, extended | 318 × 24 × 20 in (8100 × 600 × 500 mm) |
| Weight | 1,545 lb (700 kg) |
| Product groups | Group 1 or Group 2, liquid or gas |
ACTUATOR IV HYD
Propipe ACTUATOR IV HYD – Advanced Hydraulic Line Stop Actuator for 36″–48″ Pipelines
The Propipe ACTUATOR IV HYD is the most advanced hydraulic line stop actuator in the ACT series, purpose-built for isolating the largest pressurized pipelines ranging from 36″ to 48″. Engineered for exceptional power and precision, this model is ideal for critical industrial applications where safe, controlled intervention is required without system shutdown.
Its high-force hydraulic system and rugged construction make it a trusted solution for complex operations across oil, gas, petrochemical, and industrial fluid networks.
Core Functions
- Hydraulic Line Stop Operations: Deploys stop plugs into live pipelines to temporarily block flow
• Live System Isolation: Enables safe maintenance and modifications while maintaining system pressure
• High-Force Actuation: Delivers exceptional mechanical power for large-diameter, high-pressure systems
• Advanced Performance: Designed for demanding industrial environments and precision plug deployment
Key Benefits
- Hydraulic operation for high-force, precision plug setting
• Built for large-diameter pipeline isolation under pressure
• Supports safe, efficient maintenance without depressurization
• Ideal for critical infrastructure and emergency response scenarios
Specifications:
| Capacity | 36″ – 48″ |
|---|---|
| Cylinder | 10″ cyl × 4″ rod × 186″ stroke – 48″ cap |
| Mating Flanges | Special “O” ring flange |
| Max Working Pressure | 1,480 psig (102 barg) at 180°F (82.2°C) |
| Max Working Temperature | 250°F (121.2°C) at 800 psig (55.16 barg) |
| Hydraulic System MWP | 1,000 psig (68.95 barg), governed by set pressure of dual cross-line relief valve fitted to control valve |
| Max Mechanical Load | 78,570 lbf (349.5 kN), hydraulically generated mechanical thrust |
| Weight | 2,425 lb (1,100 kg) |
| Product Groups | Group 1 or Group 2, liquid or gas, as defined in the 1999 Pressure Equipment Regs |
Frequently Asked Questions
Line Stop Basics
What is a line stop actuator?
A line stop actuator drives a line stop head through a valve and fitting into a live, pressurized pipeline to temporarily block flow. This isolates a section of the line for maintenance, repair or modification without shutting down the whole system.
What is the difference between hot tapping and line stopping?
Hot tapping cuts an opening into a live pipeline through a valve and fitting. Line stopping uses that opening: once the hot tap is complete, a line stop actuator is mounted on the same valve and drives a line stop head into the pipe to block flow. See our hot tap machines.
Can line stop actuators be used on liquid and gas lines?
Yes. Every actuator in the range is rated for liquid or gas. The Actuator III HYD and Actuator IV HYD data sheets list Group 1 or Group 2, liquid or gas, as defined in the 1999 Pressure Equipment Regs.
Models and Pipe Sizes
Which line stop actuators does Enerteq supply?
Enerteq supplies the Propipe ACTUATOR series: the ACTUATOR SS MN and the ACTUATOR I, II, III and IV HYD.
What pipe sizes can be line stopped?
It depends on the model: ACTUATOR SS MN, 4″ to 12″ (SS 275-500 machine; SS plugs are set with the PCM-0204 completion machine); ACTUATOR I HYD, 4″ to 12″; ACTUATOR II HYD, 14″ to 20″; ACTUATOR III HYD, 22″ to 34″; ACTUATOR IV HYD, 36″ to 48″.
Are line stop actuators manual or hydraulic?
Both are available. The ACTUATOR SS MN is a manual line stop machine and stop plug setter. The ACTUATOR I, II, III and IV are hydraulic.
How much does a line stop actuator weigh?
ACTUATOR SS MN, 72 lb (33 kg); ACTUATOR I HYD, 297 lb (135 kg); ACTUATOR II HYD, 999 lb (453 kg); ACTUATOR III HYD, 1,545 lb (700 kg); ACTUATOR IV HYD, 2,425 lb (1,100 kg).
Ratings and Working Limits
What pressure and temperature can a line stop actuator handle?
The ACTUATOR I, II, III and IV HYD have a maximum working pressure of 1,480 psig (102 barg) at 180°F (82.2°C) and a maximum working temperature of 250°F (121.2°C) at 800 psig (55.16 barg). The ACTUATOR SS MN data sheet lists a maximum working pressure of 490 psig (35 barg) at 180°F (82.2°C), and its SS 275-500 machine is listed at max 363 psi (25 bar).
How are an actuator’s maximum working limits defined?
By two points: a maximum working pressure at a specified temperature, and a maximum working temperature at a specified lower pressure. The actuator can be operated at any pressure up to a straight line drawn between those two points on a pressure-temperature diagram. It is the end user’s responsibility to make sure the actuator is not attached to a system whose operating conditions exceed those limits.
What is the hydraulic system pressure and maximum load?
On the ACTUATOR III HYD and IV HYD, the hydraulic system MWP is 1,000 psig (68.95 barg), governed by the set pressure of a dual cross-line relief valve fitted to the control valve. Maximum mechanical load is 78,570 lbf (349.5 kN) of hydraulically generated thrust. The hydraulic system has over-pressure protection so the return side of the cylinder cannot be over-pressurized.
Dimensions and Connections
What flange connection do line stop actuators use?
All models use a special “O” ring mating flange.
How long are line stop actuators?
ACTUATOR I HYD: 72 × 14 × 7.5 in (1829 × 360 × 185 mm) retracted, 136 × 14 × 7.5 in (3440 × 360 × 185 mm) extended. ACTUATOR III HYD: 177 × 24 × 20 in (4500 × 600 × 500 mm) retracted, 318 × 24 × 20 in (8100 × 600 × 500 mm) extended. Control bar reach is 48″ (1220 mm) on the SS MN and 102″ (2642 mm) on the ACTUATOR II HYD.
What cylinder does a hydraulic line stop actuator use?
The ACTUATOR III HYD uses an 8″ cylinder × 4″ rod × 140″ stroke (34″ cap). The ACTUATOR IV HYD uses a 10″ cylinder × 4″ rod × 186″ stroke (48″ cap). The ACTUATOR II HYD has an 23.2-gallon (88-litre) hydraulic oil capacity.
Precision Modifications to Meet Your Pipeline Maintenance Requirement
We Customize to Fit Your Field Conditions for custom specifications, stroke modifications, or special-order configurations, we’re here to help. Whether you require non-standard mounting, extended stroke, or tailored hydraulic integration, our engineering team can adapt line stop actuators to meet your exact operational needs. Contact us directly to discuss your project requirements, and we’ll work with you to deliver a solution that aligns with your technical standards and field conditions.

