Mechanical Research & Design, Inc.’s combination isolation and joint test tools, also commonly known as double block and bleed tools, are designed to be user friendly, safe, multi-functional, and offer some of the highest pressure ratings and largest size ranges of any tools on the market. The tool is multi-functional in that it can provide isolation and worker safety from in-line pressures, particularly vapors and explosive
gases during hot work operations such as grinding, cutting, and welding, as well as perform the secondary operation of pressure testing welds internally once the pipe repair or connection is complete. We fabricate both mechanical and inflatable seal tools, utilizing our own SEALFAST® elastomers carefully selected to work with the widest range of chemicals, gases, and temperature ranges. Our isolation and joint test tools are commonly found in refineries, transport piping systems, pressure vessel maintenance, fabrication, and repair and pipe weldment fabrication. Our double block and bleed tools are machined and assembled in our plant with materials and coatings to serve the rugged and demanding industries in which they are used to maximize worker convenience, safety, and tool service life.
Mechanical Research & Design, Inc. combination isolation and joint test tools are simple in function and easy to use with proper training. A common mechanical isolation and joint test tool is shown below to illustrate function. When utilized in an isolation type application, the tool is slid into the pipe, past the point of repair, pipe cut-off, or weld prep. The user first tightens custom restraining screws to hold the
tool in place in the event of pressure build-up downstream. The user then actuates the dual SEALFAST® mechanical seals by tightening actuation nuts on the front of the tool. Users can then choose to pressurize between the seals to confirm redundant pressure boundaries and afterwards, bleed off the region between seals to a remote location to provide the full double block and bleed safety function of the seal. A bypass is provided through the tool on all designs to allow the user to vent downstream gases/fluids to a remote location if desired or monitor downstream pressures via gauge.
After the repair or fabrication work is complete, the user can deactuate the mechanical seals then deactuate the restraint screws, sliding the tool forward, such that a SEALFAST® Mechanical seal is positioned, one forward and aft of the weld. The SEALFAST® Mechanical seals can then be re-actuated, creating a test annulus to the inside of the weld, allowing the user to pump water into the annulus, while venting air, to allow for an effective hydrotest of the weld.
There are three customary configurations of our standard mechanical isolation and joint test tool, as detailed above. Note that our inflatable seal tools are similar but used only in specific instances. All tools can be provided with kits to make sections smaller for limited geometry applications: valve clearance, large welds, elbows, limited access in front of pipe, etc.
• CONFIGURATION 1: LARGE PIPE – DRUM STYLE TOOLS
Large Pipe Mechanical Isolation and Joint Test Tools are larger barrel shaped tools that utilize restraint screws around the circumference to lock to tool in place to resist pressure downstream and employ two SEALFAST® Mechanical seals, actuated via seal actuation nuts to provide a dual/redundant seal isolation barrier or test annulus for hydrotesting. Utilize the Test Fill and Test Vent port to pressurize and evacuate air from the test annulus and a through tool bypass as a downstream pressure monitoring or venting port. Available in isolation rated pressures from vacuum to several hundred psi and in joint pressure test ratings from vacuum to over 5000 psi. Configuration 1 Double block and bleed tools available are in ranges from 6″ and greater than 144 inches.
• CONFIGURATION 2: MEDIUM PIPE – GRIPPER STYLE TOOLS
Medium Size Mechanical Isolation and Joint Test Tools are for intermediate sized pipes that utilize gripper pads around the circumference to lock to tool in place to resist pressure downstream and employ two SEALFAST® Mechanical seals. The grippers and seals are both actuated via a seal actuation nut to provide a dual/redundant seal isolation barrier or test annulus for hydrotesting. Utilize the Test Fill and Test Vent port to pressurize and evacuate air from the test annulus and a through tool bypass as a downstream pressure monitoring or venting port. Available in isolation rated pressures from vacuum to several thousand psi and in joint pressure test ratings from vacuum to over 5000 psi. Configuration 2 Double block and bleed tools are available in ranges from 2″ and greater than 12″.
• CONFIGURATION 3: SMALL PIPE – SMALL BORE TOOLS
Small Bore Mechanical Isolation and Joint Test Tools are for small sized pipes that employ two SEALFAST® Mechanical seals actuated via a seal actuation nut to provide a dual/redundant seal isolation barrier or test annulus for hydrotesting. Utilize the Test Fill and Test Vent port to pressurize and evacuate air from the test annulus and a through tool bypass as a downstream pressure monitoring or venting port. Available in isolation rated pressures from vacuum to several thousand psi and in joint pressure test ratings from vacuum to over 5000 psi. Configuration 3 Double block and bleed tools are available in ranges from .5″ and greater than 6″.
We specialize in custom solutions! Take a look at a few of our proven custom solutions or let us know your requirements. Our engineers and production staff are equipped to travel around the world at a moment’s notice to assist you with your needs!
Contact us today to discuss our rates or to book an appointment with one of our engineers.
Mechanical Research & Design, Inc. specializes in custom, application-specific solutions. We test new ideas constantly, building better products, some not found in existence anywhere else in the world. We design Isolation and Joint Test tools with inflatable seals for remote installations to cover geometry such as elbows and pass-through valves. We also design tools that are hydraulically or pneumatically actuated, allowing tools to be set for both isolation or testing remotely. We manufacture tools to test custom pipe materials and custom joints for extreme environmental and radioactive applications, as well as custom nozzles, flanges, pipe reducers, elliptical reducers, and many more applications.
Mechanical Research & Design, Inc. has been designing and manufacturing isolation and joint test tools for over 20 years, combining our quality SEALFAST® Elastomers with industry knowledge, maximum flexibility in use, and at competitive prices. We speak with our customers to optimize our double block and bleed tooling for the largest number of applications, fits, pressures, and temperatures. Try our extensive line of standard and customized isolation and joint test tools today for your plant testing needs!
To see our other lines of isolation and test products, including plugs, joint testers and many more, click here.
If you would like more information about how we can streamline your testing processes, contact us or request a free quote today!
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