MLA Swivel Joint
1.The loading arm has long-life swivel joints that may rotate flexibly without any leakage or permanent deformation.
2.The swivel joints are strong and rigid enough to withstand combined load under the most unfavorable working conditions.
3.The swivel joints can be lubricated without being taken down, and lubricant can be easily injected.
Protection mechanism against lubricant spill is also provided. Lubricant used for the swivel joints satisfies the design temperature requirement.
4.For disassembly of the swivel joints, auxiliary devices are provided at the middle and head of the arm where the swivel joints are located, so that the primary seal of the swivel joints can be removed without the need for additional tool, and only one maintenance worker is required for replacement of the sealing rings.
5.The flange end surface of the 3D swivel joint near the tanker manifold end always remains in the vertical plane when unconnected, making the tanker connection more convenient and effort-saving.
6. Swivel joints will undergo load tests before delivery out of the factory.
7.The following figure shows the structure of a swivel joint:
8.Our swivel joints will cause rare damage to the ball track in long-term operation. The primary sealing ring is made of PTFE mixed with a certain proportion of granite, and lined with an elastic stainless steel expansion ring made of 316L after special treatment. PTFE, with good resistance to wear and aging and high sealing performance (even under high temperatures), is suitable for many media. The increased elasticity of the sealing ring by a lined spring clip may also reduce seal wear.
9. Water seal of the swivel joint functions to prevent water, dust and moisture contained in the air entering the ball track and the sealing element, so as to prolong the service life of the swivel joint. On the other hand, after installation of a water seal, an enclosed chamber will be formed in the steel ball track to make the seal more effective, because the external atmosphere will force the sealing lip to extend outwards.
10. At both ends of the swivel joint, secondary sealing rings are used to prevent leakage of grease; two rows of steel balls are mounted;
11. Each swivel joint is provided with one or several grease cup (according to the size of the swivel joint); upon filling grease, it is required to remove the two ball plugs, and use a grease cup to fill grease. Excessive grease filled may overflow from the ball plugs, so that compression of the sealing element by excessive grease can be avoided.
12.at both ends, and the other has flange at one end and weld on the other end. Swivel joints of the second form are used at 3D joints to reduce the weight, while swivel joints of the first form (i.e. with flanges at both ends) are used at other rotating parts of the arm for easy disassembly.
※ Upon lubricating a swivel joint, it is not required to disassemble the joint for preventing injection of excessive grease.
※ There are three seal types: primary seal, one secondary seal, one water seal and one grease seal.
※ Swivel joints can be detachable. Replacement of a seal ring can be simply realized without disassembling the whole arm.
※ Steel balls can be simply replaced as a whole by removing the flange, other than one by one as for ordinary joints.
※ Swivel joints with flanges at both ends can be maintained and replaced more easily and faster. When the grease seal or the water seal is worn, replacement can be performed simply by removing corresponding flange, while in the conventional structure, replacement of a water seal can be performed only after removal of the steel balls.
※ Swivel joints of the same type on the same arm can be exchanged.