Rotary Union, is called rotary joint or swivel union.
The BW series rotary unions are developed with a balanced seal and self-support design, high-precision metal bearing and an anti-shock structure, leading to high reliability and superior quality. It finds a wide application in the soft calender for paper making.
When it comes to the BWL rotary joint, it is specially designed for transferring thermal oils at a medium speed and low and medium temperature. The seal surface makes use of quenched steel and graphite to realize balanced sealing. Additionally, a group of small springs are used to offer stable fore to graphite. The BWL thermal oil joint has a protection device which introduces leaked hot oil into heating device, thus avoiding bearing block caused by the oxidation of thermal oil and worker empyrosis.
Rotary Union Structure
Rear cover, gasket, cover, PTFE shaft sleeve, lifting eye, stationary seal ring, flange, housing, quick-change flange, nipple, inner tube flange
Technical Parameters of Hot Oil Rotary Unions
Max. speed: 750RPM
Max. temperature: 195℃
Max. pressure: 1.1MPa
Media: Hot oil
1. Make sure the rotary joint is matched with supply pipe and rotating equipment. Then, clean up the joint and remove all residues and burs, thereby ensuring high concentricity and stability. What's more, the roll must stay clean and the medium should contain no impurities, preventing abrasion and breakdown.
2. The BWLR090 rotary union is equipped with an inner tube flange that improves the stability under high speed and reduces the vibration to 0-0.3mm. When installing, mount the flange onto the shaft head, the distance between the inner tube flange and inner tube surface should be slightly shorter than the length of PTFE rear cover (Shown as Figure 2). Hexagon socket head cap screw M6×20, press plate and semi ring are used for fixing the inner tube. (Shown as Figure 3)
- Figure 2 Inner tube connection
- Figure 3 Inner tube fixture
3. Connect the rotary joint with inner tube flange. Firstly, set the quick-change flange and semi-ring onto the nipple while put the copper gasket onto the inner tube flange. Fix the rotary joint with PTFE shaft sleeve and use a screw to connect the quick-change flange with inner tube flange. After fastening the screw, check and make sure the gap of two flanges is the same. (Notes: The inner tube should be prevented from colliding with the stationary ring when the rotary joint is passing the inner tube)
4. Connect the rotary joint with metal hose. The length of metal hose should be carefully chosen to guarantee no axial tension or radial tension as well as assure high concentricity and stability.
5. Rotation stop. The lifting eye is used to eliminate the rotation. The diameter of rod should be 2mm shorter than the hole.
Note: When all installation is finished, the drain hole should be linked to oil drainage tube.
1. Dismount the housing and rear cover.
2. Check the springs and see if they can bounce up the graphite. If the graphite cannot be removed, then dismount the graphite and clean up carbon produced by the oxidation of thermal oil.
3. Make sure no abrasion or scratch on the surface of graphite.
4. Check the O-shaped ring of the graphite.
5. Replace components according to the wear and damage.
6. Assemble all components together.
Note: Lubricating oil should be added to the bearing every two months.
Caution: During the disassembly, make sure no collision and knock between components and keep all parts clean. When the maintenance is finished, check if the spring can remove and impose force on the graphite.