![Automatic flux welding](http://pipe-st.com/images/bodyblock/imgp5708.jpg)
Welded monolithic construction
A welded monolithic construction has an enhanced capability to withstand mechanical loads and is convenient while installing and operating.![U-shaped double seal system](http://pipe-st.com/images/bodyblock/razrez-imm.jpg)
U-shaped double seal system
Patented U-shaped double seal system has unique sealing and dielectric properties, and has a wide range of constructive and technological advantages as compared with O-ring seal systems:
- absence of explosive decompression effect;
- applicability under a high pressure (up to100 MPa);
- applicability at high mechanical loads (tension, compression, bending, torsion);
- possibility to manufacture large diameter joints (up to 3300 mm).
Possibility of aboveground and underground installation
![Insulating monolithic joint with operating temperature of up to +250°С](http://pipe-st.com/images/bodyblock/9-1.jpg)
Applicability in all the climatic zones
Applicability in all the climatic zones including maximum operating temperature up to plus 250°C.
![Shot peening before coating](http://pipe-st.com/images/bodyblock/imgp5881.jpg)
Factory outer coating
Factory outer coating (epoxy or polyurethane) provides an effective electrical and mechanical protection against external influences.
Nonconductive inner coating
Nonconductive inner coating allows to avoid a bypass during the transportation of a conductive product.IMJ are subjected to the following types of tests
Acceptance tests and inspections. 100% of manufactured IMJ are subject to:
- Non-Destructive Testing of Welded Seams
- Internal hydraulic pressure test
- Internal hydraulic pressure cycle testing (upon Customer's request)
- Internal hydraulic pressure integrity test
- Breakdown test
- Electric resistance test
- Thickness test of anticorrosive coating
- Dielectric continuity test of anticorrosive coating
- Overall dimension and weight test
- Visual inspection
![Tests for internal pressure combined action and torque](http://pipe-st.com/images/bodyblock/foto-19122018-14-57-14.jpg)
Periodic testing (Once in 5 years). Tests are performed on IMJ of different diameters and pressure levels to confirm the design reliability of the entire range of products (randomly)
- Tests for internal hydraulic pressure combined action and bending moment
- Tests for internal hydraulic pressure combined action and torque