Prior to installation, welding can be performed within 1 pipe diameter of the Lokring connection. To prevent the ESP® technology from compromise after the fitting has been installed, welding should not be performed within close proximity of a Lokring fitting (an exact distance cannot be established due to large process variations). It is important to minimize any differential heating to the fitting-pipe interface.
The fitting can either be returned to Lokring, or the driver can be lightly tapped back in place. Drivers are pre-installed at the factory to simplify the installation. This pre-install is a light press fit that can result in the driver rings dislodging if the fitting is handled roughly. If the driver comes off, it may still be re-installed and the fitting installation may still be completed successfully.
Lokring fittings are equivalent to a weld in many ways. As is true for a weld, the Lokring fitting offers a tamper-proof connection that cannot be removed once installed. Lokring does provide a separable solution in our face seal O-ring fitting. Lokring also offers by flange and by threaded connections.
We should not try to answer a question about specific end usage; internal corrosion is the user’s judgment. Most products can be typically used on schedule 10 through schedule 80 (microalloyed steel is not accepted on schedule 10, but may work in certain applications). Lokring MAS fittings have been tested down to the wall of schedule 10.
At this time, Lokring offers only limited metric sizes. Contact your authorized Lokring Distributor for specific applications.
Available material and sizes:
30 and 44.5mm (M30 and M44.5)
6, 10, 12, 14, 15, 16, and 20mm (M06, M10, M12, M14, M15, M16, and M20)
Microalloyed Steel (MAS)
10, 12, 73, and 76.1mm (M10, M12, M73, and M76.1)
Because of our modular method of construction, Lokring can manufacture most piping configurations. Contact your authorized Lokring sales and service representative.
See your Lokring brochure and Lokring fitting specifications for material-specific, size-specific pressure-temperature ratings.
Typical temperature ratings:
|Microalloyed Steel (MAS): -20 to 650 °F (-28 to 204 °C)|
|4130 Alloy Steel (LTCS): -20 to 800 °F (-28 to 426 °C) for ASME B31.1|
|4130 Alloy Steel (LTCS): -50 to 800 °F (-45 to 426 °C) for ASME B31.3|
|Stainless Steel: -20 to 800 °F (-28 to 426 °C) for ASME B31.1|
|Stainless Steel: -425 to 800 °F (-253 to 426 °C) for ASME B31.3|
|90/10 Copper Nickel: -60 to 425 °F (-51 to 218 °C)|
|70/30 Copper Nickel: -60 to 425 °F (-51 to 218 °C)|
|Stainless Tube Fittings: -325 to 800 °F (-198 to 428 °C)|
Pressures rating vary with size and wall thickness.
“ASME does not ‘approve’, ‘rate’ or ‘endorse’ any item, construction, proprietary device or activity.” This information can be found on the back of the title page of the B31.1 and B31.3 codes. However, ASME B31 does provide nominal guidelines and requirements for the owner, designer, manufacturer, and constructor to qualify materials and piping product forms, whether proprietary or not. Under the B31 codes, the Lokring fitting would be considered a “proprietary” mechanically attached coupling.
To meet the intent of the B31 codes, Lokring:
1. Provided a design that meets the intents of B31.1 and B31.3.
2. Provided material and workmanship in accordance with B31.1 and B31.3.
3. Thoroughly tested to validate the fitting to develop product form design data in accordance with the appropriate requirements of B31.1 and B31.3. Lokring fittings may also meet the requirements of B31.4 and B31.8. Consult Lokring for more detail.
4. Developed an installation procedure for the fabricator to ensure that final assembly procedures and installation for which the design data apply.
This is not necessary. Lokring fittings are installed, and hanging requirements are the same as a welded system. Lokring does not require the back-off requirements of a socket welding. Because leaving space is unnecessary, Lokring design has superior flow path characteristics and still meets all hanging requirements similar to welding. Lokring provides a specific document for hanging and stress details. A Guideline for Designing ASME B31 Pressure Piping Using Lokring Elastic Strain Preload® (ESP®) Fittings.
NOTE: Other fittings don’t always meet the hanging requirements thus creating leaks, sagging pipes, and eventually, much higher costs.
Lokring fittings offer the performance of a welded joint. To date, the bulk of microalloyed steel (MAS) Lokring applications have been on process fluids such as solvents and gases. Lokring microalloyed steel (MAS) fittings are appropriate for typical utility applications. Lokring offers a 4130 Alloy steel for Process applications. This fitting is manufactured from NACE-qualified material and may be suitable for specific hydrocarbon and process applications.