Frequently Asked Questions

A rotary joint (also called rotary union or swivel joint) is a precision mechanical device used to transfer fluid — air, water, oil, coolant, or steam — from a stationary source to a rotating destination, or vice versa. Begapunk manufactures single-channel and multi-channel rotary joints for industrial automation, CNC machining, laser cutting, packaging, and other rotating machinery applications.

There is no technical difference — the terms are used interchangeably in the industry. "Rotary union" is more common in North America, while "rotary joint" is widely used in Europe and Asia. Both refer to the same device: a mechanical seal assembly that transfers fluid between stationary and rotating components.

The key parameters are:

• Media type: Air, water, coolant, hydraulic oil, steam, or other
• Number of passages: 1-in-1-out, 2-in-2-out, 3-in-3-out, or custom multi-channel
• Max pressure: In bar or psi
• Max speed: In RPM
• Connection type: Threaded (NPT/BSP) or flange mount
• Mounting space constraints: Any dimensional limitations

A machine drawing is helpful but not required. Most quotes are returned within 24 hours.

Our standard rotary joints handle: compressed air, water, water-soluble coolant, hydraulic oil (up to ISO VG 32), and thermal oil. The PTFE composite seals are compatible with most common industrial fluids. For steam, aggressive chemicals, or food-grade applications, please contact our engineering team for material recommendations.

Our product range covers a wide performance spectrum:

• Standard models: Up to 1 MPa (10 bar / 145 psi) and 500 RPM
• Heavy-duty models: Up to 10 MPa (100 bar) and 2,000 RPM
• High-speed models: Up to 10,000 RPM (air only, balanced seal design)

For requirements beyond these specifications, we design custom solutions. Send us your parameters for a feasibility assessment.

Yes — that's exactly what our multi-channel rotary joints are designed for. Each passage has independent seals and isolated flow paths, so there is zero cross-contamination between channels. Common examples:

• 3-channel: Oxygen + Nitrogen + Coolant in laser tube cutting machines
• 2-channel: Compressed air + Vacuum in packaging machinery
• 6-channel: Hydraulic oil + Cooling water + Grease in wind turbine pitch systems

Material selection depends on the application:

• Body: AL6061 aluminum (lightweight, anodized blue), 45# steel, 304 stainless steel, or 316 stainless steel
• Shaft: 45# steel, 304 SS, or 316 SS
• Seals: PTFE composite (standard), carbon fiber, graphite, or ceramic

Custom materials available upon request for corrosive environments, high temperatures, or food-grade applications.

Yes — custom design is our specialty. Our engineering team will work with you to design a rotary joint for any number of passages, pressure, speed, mounting type, and material. Process:

• You send requirements → We provide a detailed quote within 24 hours
• Upon order confirmation → We provide a free 3D STEP file for fit verification
• You approve the design → We manufacture (typically 3 weeks)
• 100% pressure tested → Shipped to your door

Start your custom inquiry →

Standard models: 1 piece. Custom designs: typically 5–10 pieces for the first order. We understand the need for prototypes and samples — there is no penalty for small orders.

Delivery times depend on the product type:

• Standard models (in stock): 7–10 days worldwide via air freight
• Custom designs: 3 weeks production + 5–7 days shipping

DDP (Delivered Duty Paid) terms available — we handle customs clearance and import duties for you.

All Begapunk rotary joints carry a 12-month replacement warranty from the date of delivery. The warranty covers material defects and manufacturing defects. If a seal fails within warranty due to a covered defect, we ship a replacement unit immediately — return of the defective unit is not required. See our Terms of Service for full details.

Yes. Every single rotary joint undergoes 100% pressure testing at 1.5× rated pressure before leaving our Ningbo factory. Our quality management system is ISO 9001:2015 certified. Test records are available upon request.

Yes — free of charge. We provide STEP and IGES files for all standard models. For custom designs, we provide 2D drawings for approval before production, and 3D files with the shipment. This allows your mechanical team to verify fit and mounting compatibility before ordering.

We offer two standard mounting types:

• Threaded mount: NPT or BSP threads — connect directly to your equipment
• Flange mount: Bolt-on flange with O-ring face seal — provides rigid, leak-free connection

Custom mounting configurations are available. Important: Always use flexible hose connections — never hard-pipe a rotary joint. See our Installation Guide for details.

The most common causes of premature failure are:

• Hard piping: Rigid connections transfer vibration and misalignment to bearings and seals
• Side-loading: Hoses under tension or sharp bends apply lateral force to the joint
• Contamination: Unfiltered media grinds grooves into seal faces — use 25 micron or finer filtration
• Over-speed / over-pressure: Exceeding rated specifications
• Rigid anti-rotation: Anti-rotation devices must allow the joint to self-center

Following our Installation Guide will prevent most of these issues.

Yes. Most Begapunk rotary joints can be rebuilt using OEM seal kits. We strongly recommend using only Begapunk seals — third-party seals may have incorrect durometer (hardness) or material, leading to premature leakage. Contact our support team with your product serial number to order the correct seal kit.

Begapunk requires fluid filtration to 25 microns or finer for general applications, and 10 microns or finer for high-speed or precision rotary unions. Contaminants larger than the seal gap will embed in the seal material and cause irreversible shaft scoring. Inadequate filtration may void your warranty.