The Line Went Down and the Trucks Started Running
Plant engineers at a petrochemical facility on the Houston Ship Channel were dealing with multiple leaks along a six-inch discharge line. The line carried treated wastewater from the facility out to a discharge point, and the route between the two runs roughly three and a half miles. Pipeline rehabilitation without digging was not the question yet. Stopping the leaks was.
The leaks were not the expensive part.
Because the line was compromised, the facility was inadvertently discharging treated wastewater into the surrounding soil. Management judged that unacceptable and took the pipeline out of service. The wastewater still had to reach the discharge point, so the operator began trucking it there daily, at considerable expense, and kept trucking it for as long as the line stayed down.
That is the detail worth holding onto before any of the technical discussion. The shutdown solved the environmental problem and started a meter running on the operating budget, which is what turns a rehabilitation method into a schedule question rather than a preference. Every week of review had a number attached to it. Lines like this one run under paved ground and across property a plant cannot casually open up, which is why so much refinery and petrochemical pipe lining work starts with an asset that is already down. That is the condition Hill Services was brought into here.
Open cut was the assumed answer. Three and a half miles of trench across working ground is a project measured in months, and the ground it crosses is the part nobody wants disturbed. Trenchless pipe rehabilitation exists for the case where the pipe has to come back and the site cannot be taken apart to bring it back.
Pipeline Rehabilitation Without Digging Was Not What the RFQ Asked For
The facility’s engineers issued a request for quote to rehabilitate the line using cured-in-place pipe, or CIPP.
CIPP is a reasonable first instinct and Hill Services is a seasoned CIPP contractor, so bidding the job as written would have been the easy move. That is not what happened. Reviewing the length of the run and the pressure requirements of the discharge line, Hill’s personnel concluded that a Primus Line installation would be faster and more economical than the method the RFQ specified, and proposed it instead of the method the plant had asked for.
Hill won the bid by proposing something other than what was requested. That is the real argument of this project. The contractor who says the spec is wrong before the job starts is worth more than the one who quotes exactly what the RFQ asks for, because a low bid against the wrong method is a schedule and a budget built on an assumption nobody tested.
CIPP is primarily a gravity and lower-pressure solution. A pressure application over a run this long is a different problem, and the difference shows up in the installation time and the invoice rather than in the bid documents. Buyers across Houston and the Gulf Coast often meet that distinction after the liner is already in the ground, which is the expensive place to learn it.
Clean the Line, Prove It Is Clean, Then Line It
The field sequence ran in three steps, in this order:
- Air pigging. The crew cleaned the host pipe by air pigging, moving debris through the line without introducing the water volume that flushing a run of this length would require.
- Video inspection. The line was then video inspected end to end to verify that the cleaning had actually worked, before any liner was committed to it.
- Liner installation. With the pipe clean and the condition documented, the crew installed Primus Line Low Pressure Liner for approximately 16,000 linear feet.
Step two is the one that gets skipped. Cleaning that looks finished from the access point is not the same as cleaning confirmed along the whole run, and on a line this long, finding a problem after the liner is in place is not a rework item. It is a second project.
What the Liner Did to the Schedule and the Numbers
The product is built for this length of work. Primus Line pulls in single runs of up to 8,200 feet, installs at speeds of up to 10 meters per minute, and carries a service life of more than fifty years. It uses no adhesive and no grouting, because the annular space between the liner and the host pipe is intentional. The aramid reinforcement carries the operating pressure, and the old pipe becomes the conduit holding the new one in position.
Hill Services is the only certified Primus installer under contract for industrial oil and gas in the United States.
The project finished under budget and on schedule, and the facility resumed normal use of the discharge line. The project record puts the installation at four weeks and the work at roughly one third of the cost and time of conventional CIPP, and notes that the client reported an increase in flow rate afterward. Trenchless rehabilitation is generally reported to run 30 to 50 percent below open-trench replacement, so the shape of that saving is ordinary. The multiple on this job is a record of this job, not a quote for the next one.
Better flow through a lined pipe than the pipe had before it was lined. That result surprises engineers who assume a liner is a compromise on capacity.
Frequently Asked Questions
How Long a Run Can Be Rehabilitated Without Excavation?
Primus Line installs in single pulls of up to 8,200 feet, and pulls can be sequenced along a longer route. On this line, approximately 16,000 linear feet was lined in place.
Is Trenchless Lining Only for Gravity Sewer Lines?
No. CIPP is primarily a gravity and lower-pressure method, while a reinforced pressure liner is built to hold the full internal operating pressure without depending on the host pipe for structural support. Getting that distinction settled at the specification stage, rather than after award, is what decides whether the repair holds.
Does the Line Have to Be Out of Service?
The line is isolated for the work, so the job is scoped around an outage rather than around continuous flow. The comparison that matters is not lining versus running. It is a defined outage of weeks against an open-cut replacement measured in months.
What Changes When the Method Is Questioned Before the Bid
The trench never happened, which matters. But the decision that changed this project happened before any equipment reached the site, when a contractor read an RFQ for one method and said the line wanted a different one. The schedule, the budget, and the end of the daily trucking all followed from that.
Refineries and petrochemical plants are full of lines like this one. Long, pressurized, buried under ground that cannot be opened, carrying media that cannot be released. The method that fits is decided by length, pressure, media, and access, not by what was written into the request.
How Hill Services Approaches This
Hill Services runs the camera and reads the conditions before recommending a method, which is why the recommendation on this job did not match the request that started it. To discuss a discharge or process line that is out of service, or one heading that way, request a project estimate or call Hill Services at (901) 388-7500.