Specialty Mechanical Services

At On Site Services Ltd., we provide routine maintenance and specialty mechanical services for the petrochemical and oilfield industries. Allow our experts to field machine and flange face your damaged flanges, vessels, convertor heads, and manways. We can also cut and bevel a variety of piping. Additionally, we offer on-line leak sealing of piping, valves, and exchangers.

Some of our in-depth services include:

Industrial Element

Past Jobs

Hot Tapping & Line Stopping

Hot Tapping is the capability to safely tie into a pressurized system by drilling while it is on stream and under pressure.
Lead Plating Pipe
Drilling Machine Figure

Our company stocks specialized equipment (hot tap tool, cutters, and housings) that can perform hot taps up to a 12-inch diameter. We have competent and trained staff on a permanent basis to cater for dynamic applications regardless of the pipe material and/or the fluid content. Our team can also source fittings, valves, and cutters to suit your needs.

Pipeline Stops
Line Stops

Line Stops are used to temporarily shut down a pipeline system to complete modifications or repairs. They allow a system to operate without any interruption in service. This is typically done in conjunction with hot tapping.

Mechanical Scraper Exchanger Tube Cleaning

We provide innovative solutions for achieving maximum efficiency and reliability to your plant cooling water systems. Whether it is a large 40,000 tube condenser or small shell and tube heat exchanger, On Site Services Ltd. has the experience, knowledge, and right products to cope with differing conditions and sometimes unique challenges that each situation presents.
Applications: For cleaning tubes in Heat Exchangers, Condensers, Chillers, Absorbers, Water Heaters, Coolers, and other small diameter pressure vessels.

Mechanical Scraper System

The ultimate tube cleaning solution for Condensers, Heat Exchangers, Coolers, and more. The Mechanical Scraper System uses our unique booster pump to generate low-pressure water to propel specially designed cleaners down the tubes cleaning as they go.
The cleaners are loaded in batches, and it is clearly identifiable to see which tubes are to be cleaned. The operator then fits the gun into each tube and pulls the trigger to release the low pressure, high volume water flow to power the cleaner through each tube. A dial on the water gun indicates when the cleaner has exited the cleaned tube.
Mechanical Scraper System
The operator continues this process until all the tubes have been cleaned. The cleaners come in a variety of designs, materials, sizes, and gauges to suit the cleaning needs of your condenser tubes.
Pipeline Cleaners
The Mechanical Scraper System can remove a wide range of deposits from algae to hard scale without damaging the wall of the tube. Using a two-pump system, up to 8,000 tubes a shift can be cleaned. Our alliance partner has been cleaning tubes with this process very successfully for the past 15 years in the UK and around the world.
Cleaning on a regular maintenance schedule can offer you the following benefits that will ultimately save you money:
In fact, there have been many occasions when the cost of the cleaning has paid for itself in a matter of weeks.

Bolt Torquing and Tensioning

On Site Services Ltd. conforms to the ASME-PCC-1 2016 – Guidelines for Pressure Boundary Flanged Bolted Joint Assemblies. To date, we have a Leak-Free record!
We have trained, experienced and certified technicians that are capable of assessing the specific requirements for most bolted assemblies. We will complete joints safely, timely, and efficiently.
Bolt Torquing
Bolt Tensioning
Bolt Torquing and Tensioning


Recent Projects

We will guarantee NO LEAKS on startup with this system (once parallel joint closure and Hytorc equipment are used).

Integrity Pressure Testing, Hydrostatic/ Pneumatic Testing / Field Weld Testing, and Double Block and Bleed Isolation for Welding

Safe, Effective Solutions for Rapid Testing

We are the leader in our field. Our personnel is trained, certified, and experienced. Our equipment can suit your needs; whether it’s a manifold or 1000ft (24-inch diameter) pipe, we have the resources to support both on-shore and off-shore applications. We stock a variety of Hydrostatic Test Pumps and accessories, inclusive of monitoring/recording devices, pressure relief valves, hoses, and connections. Our equipment is regularly tested and serviced, calibrated, and third-party certified.
Integrity Pressure Testing
Hydrostatic Test Pumps
Hydrostatic Test Pump Equipment
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On Site Services Ltd.’s service of field weld testing for pipelines and vessels includes the use of a complete line of hydrostatic test plugs and double block and bleed isolation plugs. Test plugs provide safe and effective testing at working pressures up to 14,000 psi (960 Bar). Pipe OD and ID sealing versions are available, along with isolation bags and single block plugs. Whether it’s isolation or testing, we have the right equipment. Isolation plugs are designed for quickly isolating and testing weld joints of any welded flange-to-pipe connection, as well as isolating pipe ends during cutting, grinding, and welding operations.
Hydrostatic Test Plugs
Double Block Plugs
Bleed Isolation Plugs

Leak Sealing & Pipe Plugging

If you have a leak, contact us for consultation. We can have an experienced staff member at your location for a site visit to determine your needs and aid in developing your repair plan.
We can guide you on leak repair applications, procedures, pipe clamps, pipe plugging, compatible sealant for your requirements, and pipe wrapping specifications and installation. We design, manufacture, and install a wide range of pipe clamps suited for most leaking applications. Injectors, sealants.
Leak Sealing
Send us a drawing, line information, material specifications, fluid specifications, and environmental conditions. Our team will send you a quotation within 24 hours of a site visit, and we can supply pipe wrapping materials in just two weeks of issuing your purchase order.
We have experienced staff that can install in most environments. Process piping, exchangers, valves, injectors, we have successfully done them all. We can provide custom installation procedures that are specific to your needs and application.
Pipe Plugging
Pipe Clamps

Pipe Cutting, Flange Facing & Field Machining

Pipe Cutting

We can precision cut and bevel piping from 2-inch to 43-inch regardless of material, schedule, or location. We have the equipment and blades ex-stock. On Site Services Ltd. retains permanent personnel to supervise and perform cutting and beveling for shutdowns, turnarounds, and routine workshop fabrication.
Demolition required? We have the right equipment. A High-Power Pneumatic Hacksaw that will cut through almost anything!
Pipe Cutting Device
High-Power Pneumatic Hacksaw

Flange Facing and Field Machining

Specialist Stud Extraction – Exchanger studs seized? We can offer a quality service, private consultation, and innovative equipment! We can machine and reface flanges using ID or OD mount facing tools.

Recent projects

Flange Facing Machine

Chemical & Corrosion Management

Protect your assets with good corrosion and chemical management from On Site Services Ltd. We provide the expertise needed to ensure your operations run smoothly. We design, monitor, and consult on a wide range of corrosion and chemical application projects.

Providing Our Expertise

In the oil and gas industry, Integrity Management plays a significant part in ensuring assets are protected. Our expertise in this area is required during project design and ongoing asset integrity management, especially when this expertise does not reside within your company’s employee pool.
Also, chemical corrosion inhibition is a major part of internal corrosion mitigation. Chemical treatment programs are also critical to operations in other areas – scale control for water-containing systems, hydrate inhibition for gas systems, demulsification for oil-water separation both on-shore and off-shore, etc.
We have on-staff engineers and field resources to completely handle both these areas on a contract basis. This can be for a new facility or existing assets where “getting a handle” on this area has been problematic.

Services provided here include:

These services apply to Refineries, Process Plants, upstream Oil and Gas Production, Gas Transport, and Water Companies.

We are the sole representative for Metal Samples (ALSPI) in the Caribbean

Metal Samples is one of the world leaders in corrosion monitoring. Corrosion is the leading cause of process equipment and piping failure, requiring companies to pay billions of dollars annually in replacement costs and downtime. We offer a wide range of solutions to corrosion problems in a variety of industries, including oil and gas, petrochemical, water treatment, chemical, pulp and paper, and pharmaceutical. Since 1990, we have introduced a continuous stream of products that help customers obtain and analyze corrosion data that was previously inaccessible.
Products include internal corrosion monitoring systems (coupons and probes). Many of the systems can operate using discrete monitoring and online monitoring systems that can be hooked up to Distributed Control Systems.

Remote Corrosion Monitoring - Telemetry System

This remote telemetry system obtains real-time corrosion monitoring data via the Internet from anywhere in the world. The system features communications via satellite to a secure Web Monitor data server. With this powerful web-based back end, you can bring the data to your desk no matter where the site is located.
Solar Panel

System Benefits Include:

The built-in solar panel powers the Base Station, allowing for use when local power is not available. Using its internal battery and charge control circuit, the unit functions in the ‘Monitor & Sleep’ mode and can operate unattended for many years.
This 4-input system allows data from up to four corrosion monitoring sites to be transmitted. The system will send a daily reading of each monitoring point. The web server will maintain a history for each site, allowing you to review the data and calculate corrosion rates from various user-selectable time periods.

Our Supervisors and Technicians are experienced and certified in all applicable services, which include:

Fuel Oil Tanks

Chemical Treatment Programs

Chemical corrosion inhibition is a significant part of internal corrosion mitigation. We provide consultancy and monitoring of your chemical treatment operations.

Chemical treatment programs are critical to the operation in other areas, such as:

Staff & Resources at the Ready

At On Site Services Ltd., we have on-staff engineers and field resources to handle all areas on a contract basis. This can be for new operations or for existing assets that have had issues with these areas. We ensure that all pipeline operations run correctly and successfully.

Cathodic Protection

Allow the experts at On Site Services Ltd. to conduct routine monitoring and maintenance with our range of cathodic protection services.
Rectifier Unit Box

These in-depth services include:

We provide cathodic protection solutions to the Oil, Gas, Petrochemical, Water, and Power Industries in the following applications:
We offer a full range of services to meet client requirements, from initial advice and support to complete turnkey systems. We can provide:
Contact On Site Services Ltd. to learn more about our products and services.