Type N Style I Unpacked Ball Joints, 2-1/2″ to 48″ NPS

Information at a Glance


6600 Hyspan Barco Ball Joints




1/2-48 in. / 12-1200 mm


≤100, 150 & 300 PSI / 3, 10 & 20 Bar



Canadian Registration


This product is registered throughout Canada under
CRN 0D9278.59870YTNADD3

Other Products

Product Description

Type N Style I ball joints have been widely accepted since the design was introduced in 1960. They are commonly used in steam, hot water, chilled water, petroleum and chemical piping to absorb thermal expansion. Common applications are tank and building settlement, seismic isolation, bridge movement and wave motion compensation in addition to steam and hot water distribution systems.

Standard models are available as weld end or flanged with optional seal materials. The total flex angle varies with size from 15º to 31º. Refer to Column 3 of the Dimensional Data below.

Standard materials are wrought steel for the ball, case and retainer. The ball sealing surface is protected with crack free chrome plating and coated with molybdenum disulfide.

Part Number

Part Numbers
BB-31533 (150 lb.)
BB-31536 (300 lb.)

Technology & Advantages

Flex torque is the moment (ft.-lbs.) at break-a-way to angularly displace a ball joint. Because the pressure thrust is reacted by the seals the flex torque is a function of pressure as illustrated by the adjacent charts for Number 11 composition seals. The values for Number 24 glass filled Teflon® seals are 15% less than the Number 11 seal values.

The values given are for steam service. For water or oil service the torque values are 45% less.

Flex Torque Type N Style I Ball Joints Number 11 Composition Seals

Seal Number 11

Compound 11 is a pressure molded proprietary seal compound recommended for general purpose applications for steam, hot water and oil systems. Compound 11 has the highest pressure/temperature ratings of the available seal materials.

Rated for service at temperatures from -50º F to +525º F.

Seal Number 24

Compound 24 is pressure molded proprietary compound of glass fiber and Teflon®. The addition of the glass fiber adds strength and stability to the seal. The compound is chemically inert and is recommended for applications involving corrosive fluids when a higher pressure rating is required.

Rated for service at temperatures from -325º F to +425º F.

Number 24 Glass Filled Teflon® Seal Part Number BB-31020, BB-31533 & BB 31536 Weld End, 150 lb. & 300 lb. Flanged

Installation and Maintenance Procedures

Proper application and maintenance of ball joints is important.

Installation Recommendations

  1. The media flow direction can be from either end of the ball joint except for liquids with suspended solids, then flow should be from ball end to casing end.
  2. In vertical installations, ball joints should be installed with the ball end down to prevent foreign matter from collecting between neck of ball and retainer.
  3. Do not loosen the ball joint retainer during installation, or utilize ball joints as Unions. Each joint is factory preset and tested before shipment. LOOSENING OF BALL JOINT RETAINER IS NOT RECOMMENDED. If the retainer must be loosened, loosen the bolting 1/4 revolution maximum using a standard crossing pattern. Retighten the bolting using the procedure outlined in Paragraph 2 of the Maintenance Instructions below.
  4. Use CAUTION PREHEATING, WELDING, OR POST WELD HEAT-TREATING ball joints into the line. Excessive heating of the sealing area may cause leakage.
  5. Protect the exposed ball surface from weld splatter, and prevent dirt and debris from collecting around neck of ball.
  6. Although ball joints can be rotated or twisted around the centerline, they are designed to absorb motion by the Offset Method that utilizes angular flex to provide the required movement. Consult a Hyspan Barco sales representative or contact Hyspan by email at websales@hyspan.com if an application involves extensive rotating motion.


Type N Style I Hyspan Barco Ball Joints are not designed for maintenance to be performed while the system is pressurized. DO NOT PERFORM ANY ADJUSTMENTS TO A BALL JOINT THAT IS PRESSURIZED.


To correct leaks or to perform routine maintenance:

  1. Relieve the internal pressure.
  2. Tighten retainer bolting to a maximum of twice the factory torque settings that are given below. Use a standard crossing pattern.

Number 11 Composition Seals

Nominal Size(s) Factory Torque (ft.-lbs.)
2 1/2" & 3" 12 to 15
4", 5" & 6" 40 to 50
8" through 30" 80 to 90

Number 24 Glass Filled Teflon® Seals

Nominal Size(s) Factory Torque (ft.-lbs.)
2 1/2" 4-5
3" & 4" 8-10
5" & 6" 12-14
8"-14" 24-26
16"-24" 20-24

If leakage still occurs the ball joint can be disassembled for maintenance

3. TO DISASSEMBLE the ball joint for maintenance it must be removed from the system.

  1. Disassemble by loosening the retainer bolts and removing the retainer.
  2. Inspect the inner seal for wear: The inner seal is seldom worn enough to require replacement. It is recommended that the outer seal should be replaced.
  3. Clean and inspect ball surface carefully. Replace the ball if it is worn, scored or pitted.
  4. Replacement balls and seals are available from an authorized Hyspan Barco representative or by contacting Hyspan by email at websales@hyspan.com. Be certain to dispose of the discarded seals properly.
  5. To reassemble, coat the surfaces of seal(s) and ball with a light coat of assembly lubricant. For service over 350º F use molybdenum disulfide based lubricant.
  6. If the inner seal has been removed, install it in the case with the concave surface out by tapping it in place evenly with a soft mallet.
  7. Slide new outer seal over extended end of ball with the concave surface mating to the convex surface of ball.
  8. Replace ball into case.
  9. Tap the new outer seal evenly with soft mallet into casing around ball.
  10. Replace the retainer tighten the bolting to the factory settings given in Paragraph 2 above.

Ordering Information

To order or specify Hyspan Barco Ball Joints state the complete part number which includes; the basic Assembly Number selected from the illustrations, the Size Code from Column 2 of the Dimensional Data tabulation and the Seal Code based on the seal composition required.




Hyspan products are available from Sales Representatives and Distributors, or they can be purchased direct from the factory. The minimum factory order for open account customers, COD shipments, or bank card sales is $100.00 (USD). All major credit or debit cards are accepted. The minimum order for new account applicants is $100.00. Our Confidential Credit Application can be downloaded and forwarded to Hyspan for processing. All orders are subject to the following Terms and Conditions, and the above warranty applies to all material. Please read these documents.

Terms and Conditions

Confidential Credit Application (13.9 KB), can be completed on line.