Line Stopping Fitting Installation
Line Stopping Services for Municipal and Commercial Water Mains
Line stopping, also called pipeline stopping, is a temporary point shutdown on a live water main: a plug is inserted into the pipe under pressure, the section remains isolated for the duration of the job, and the rest of the system remains in service. A single stop isolates flow moving in one direction; a dual stop, one on each side of the work area, isolates a section fed from both directions in a grid system. We've run line stop crews on Houston-area mains since the mid-1970s, and we stock the fittings and equipment so a temporary shutdown doesn't turn into an extended one.
Request a quote for line stopping services, and we'll scope the right method for your main.
How Line Stopping Works
A water main line stop uses a size-on-size tap on top of the main to insert a rubber plug, which a hydraulic ram drives into the pipe while the line stop sleeve supports the assembly. The plug seals the line without draining it, so the section stays isolated at working pressure for as long as the job takes. Once the work is done, we remove the plug and install a blind flange on the sleeve to permanently close out the tap.
This method is for shutdowns of three days or less; for anything longer, a permanent fix like an insertion valve is usually the better call (more on that below).
- Inspection: We expose the section of the main and confirm pipe material, diameter, and condition against the job spec before installing anything.
- Tap and plug insertion: We install the line stop sleeve, make a size-on-size tap, and drive the rubber plug into the main with a hydraulic ram until flow stops.
- Service window: With the section isolated, the repair, connection, or maintenance work the stop was scheduled for gets done.
- Stop removal and blind flange install: We pull the plug, close out the tap with a blind flange on the sleeve, and bring the main back to full flow.
Line Stop vs. Insertion Valve
A line stop is temporary by design, built for shutdowns under three days. When a project needs a permanent shutoff point for a future connection, a valve that needs replacing, or a section of main that needs isolation capability going forward, an insertion valve is the right call rather than a line stop.
The two methods solve different problems: a line stop completes the job without an outage and then goes away; an insertion valve adds a valve that remains in the system. If you're not sure which one your project needs, tell us the scope when you request a quote, and we'll recommend the right one.
Advantages of Line Stopping
Line stopping trades a full main shutdown for a temporary tap, and that trade-off is why municipalities and contractors choose it over coordinating a shutdown through existing valve infrastructure:
- Minimizes disruption: keeps service interruptions and water loss limited to the isolated section instead of a larger part of the grid.
- Flexible scheduling: skips the back-and-forth of coordinating a main shutdown with local authorities.
- Lower contamination risk: keeps the main pressurized instead of draining it, which cuts the risk of contamination during the work.
- Crew efficiency: cuts crew time on site and avoids scheduling around off-peak hours.
- Cost-effective: saves time and cost across the job compared to a full shutdown.
Line Stopping Methods We Offer
Which method we use for a line stopping job depends on the main's operating pressure, its pipe configuration, and how long the shutdown needs to last. All five run on the same underlying principle, isolating a section without draining the main, but each fits a different set of conditions:
- Standard Plug: our default method for most line stop jobs.
- High Pressure Bullet: used on higher-pressure mains where a standard plug isn't rated for the job.
- Folding Head: for taps where the pipe configuration calls for a folding plug head instead of a standard one.
- Line Freezing: isolates the section by freezing the water inside it rather than inserting a mechanical plug.
- Inflatable Plug Stopping, also called a balloon stop,: uses an inflatable plug instead of a rigid one.
Often referred to as line plugging or line stopping, these services are finely tuned to ensure minimal disruption and maximum efficiency for each unique project, affirming Mickie Service Company's commitment to excellence in pipeline management and care.
Pipe Materials and Capabilities
Line stopping works within the same pressure, temperature, and material range across every method we offer. A standard line stop holds up to 150 psi and 200°F, and covers PVC/C900, ductile iron, cast iron, asbestos cement, steel, Gifford-Hill concrete cylinder pipe, and HDPE, across water, sanitary sewer, and storm sewer lines.
Pipe Diameter Range
Line stop fittings run from 2 inches up to 60 inches, covering everything from a small commercial branch line to a large-diameter municipal transmission main.
Available diameters:
2", 4", 6", 8", 10", 12", 14", 16", 18", 20", 22", 24", 26", 28", 30", 32", 34", 36", 38", 40", 42", 44", 46", 48", 50", 52", 54", 56", 58", 60"
Line Stopping Service Area
Our municipal line stopping crews run across Houston-area cities, including Bellaire, West University, Jersey Village, Katy, Rosenberg, Pearland, Friendswood, League City, Baytown, and Shenandoah, with same-day or next-day scheduling guaranteed on standard taps of 12 inches and smaller.
Larger-diameter stops and jobs outside the immediate Houston area are scheduled case by case; see our service pages for Texas, Arkansas, Oklahoma, and Louisiana for coverage across the rest of the region.
For work outside Houston, we offer Texas line stopping and Oklahoma line stopping, along with Arkansas line stopping and Louisiana line stop service.
Pipe Diameter Capabilities
Line Stops are performed in sizes ranging from 2 inches to 60 inches.
| 2 inch | 12 inch | 22 inch | 32 inch | 42 inch | 52 inch |
| 4 inch | 14 inch | 24 inch | 34 inch | 44 inch | 54 inch |
| 6 inch | 16 inch | 26 inch | 36 inch | 46 inch | 56 inch |
| 8 inch | 18 inch | 28 inch | 38 inch | 48 inch | 58 inch |
| 10 inch | 20 inch | 30 inch | 40 inch | 50 inch | 60 inch |
What Working With Mickie Looks Like
A water line stop on a live main only works if everything is staged before the crew arrives: the right fitting already in inventory, a project manager coordinating the schedule, and documentation your team can reference once the job is done. Here's what that looks like on a line stop job:
- Same-day or next-day service on standard size stops
- Large on-hand inventory of line stop fittings
- Full-time project manager and office staff managing all service aspects
- Extensive knowledge of local specs and long-standing inspector relationships
- Highly trained, experienced technicians
- Real-time job checklists provided at the end of every job and stored permanently for future reference
How Does the Line Stopping Process Work?
Water Line Stopping Procedure and Process
If you are in need of a permanent valve solution, we offer municipal insertion valve service, as well. Mickie Service Company’s line stopping significantly reduces overtime costs and decreases repair and maintenance time.
1. Install Water Line Stop Fitting
The process begins by preparing the affected section of the water main with the installation of a specialized line stop fitting. This fitting is crucial as it allows future operations without affecting the overall system. It serves as the primary anchor point for all subsequent steps, ensuring that the isolation of the water flow can be achieved precisely where needed without disrupting service to the entire network.
2. Make Tap on Water Main
Once the fitting is securely in place, a precise tap is made on the water main. This involves creating an opening that provides access to the water main's interior, enabling the introduction of equipment necessary for stopping water flow. Careful execution of this step is vital to maintain the integrity of the main while preparing it for the insertion of the stopping plug.
3. Insert Line Stopping Plug in Housing
Following the tap, a line-stopping plug is positioned within the prepared housing. This plug acts as a temporary stop, isolating and controlling water flow through the segment of the pipe designated for maintenance or repair. Ensuring a tight and secure fit, the plug maintains the main's overall pressure conditions, allowing work to proceed safely.
4. Mount and Activate Line Stopping Equipment
After the plug is inserted, the line-stopping equipment is mounted and activated. This specialized equipment stabilizes the plug and manages water pressure within the isolated section. Its activation guarantees an effective seal, crucial for conducting maintenance without causing service interruptions or pressure-related issues in other parts of the main.
5. Perform Required Service and Installation
With the line stopping measures securely in place, technicians can safely perform necessary services or installations. This period can involve various tasks, such as repairing leaks, installing new components, or conducting routine maintenance, all performed without affecting the overall water supply,- thanks to the temporary stoppage.
6. Remove Equipment and Install Blind Flange
After completing the service tasks, the stopping equipment and plug are carefully removed. This allows for the installation of a blind flange over the original tap point. The flange ensures a permanent seal over what was once an access point, restoring the integrity of the water main and allowing normal operations to resume efficiently.
Ready To Start Your Project?
Leveraging our core capabilities in water main tapping – we now provide line stops, insertion valves, and private fire line installation.
Frequently Asked Questions About Line Stopping
Can you perform a line stop on pipe that's already damaged or corroded?
A line stop needs a section of pipe sound enough to hold the tap and support the plug assembly. If the main is already damaged or heavily corroded at the planned tap point, tell us before we scope the job. In some cases, we can shift the tap to a sounder section nearby; in others, a different repair approach fits better.
How do I know if my project needs a single stop or a dual stop?
That depends on how the main is fed. If water only reaches the work section from one direction, a single stop isolates it. If the section can be fed from both directions, which is common in grid systems, a dual stop, one on each side, isolates it completely. Tell us the pipe layout when you request a quote, and we'll confirm which setup applies to your project.
What do we need to have ready before your crew arrives?
Not much beyond clear access to the work section. We'll want any as-built information you have on the main, material, diameter and depth, so our crew can confirm the tap point before showing up. If the job needs traffic control or an excavation permit for the dig itself, flag that when you request the quote so it's scheduled alongside the crew.
Explore Our Other Water Main Services
Line stopping is one of several methods we use to work on a live water main.
If your project needs a permanent tap instead of a temporary shutdown, our hot tapping service covers that, and our insertion valve service handles permanent isolation points. For concrete cylinder pipe specifically, we offer concrete steel cylinder line stopping rather than treating it as a variation on standard line stopping.
We also handle mechanical services and emergency response under the same live-line approach.
