BlackHawk Seals – The RBR Buffer Seal

The BlackHawk RBR Buffer Seal

The RBR Buffer Seal by Blackhawk Seals is a uni-directional rod seal designed to function as a buffer seal, protecting the primary rod seal from high pressure intensification and impulses. The RBR Buffer Seal provides the majority of the sealing function, while allowing a small amount of fluid bypass to assist in the pressure actuation of the primary rod seal. The use of the RBR Buffer Seal will greatly extend the life of the primary rod seal by protecting it from excessive pressure conditions. Pressurized fluid between the RBR Buffer Seal and the primary rod seal is allowed back into the cylinder via the slotted outside diameter rib, flexible outer sealing lip and side wall slots. This relieving function prevents excessive pressure build-up between the RBR Buffer Seal and the primary rod seal, which results in the premature failure of the primary rod seal due to excessive frictional heat build-up and seal extrusion. A high-performance Backup Ring is nested into the Buffer Seal inside diameter to prevent seal extrusion at high pressure and elevated temperatures. Both ID and OD sealing lips are knife trimmed to provide reliable sealing performance.

The RBR Buffer Seal is a dual element seal design made from a high grade of water resistant polyurethane material that can withstand the inherent strain of heavy duty mining and mobile cylinder applications. The Backup Ring provides superior extrusion resistance during high pressure operation and allows for increased extrusion gaps. When used in conjunction with a high performance primary rod seal, the RBR Buffer Seal provides extended service life and effective zero leakage sealing performance for medium and heavy-duty cylinder applications.

The RBR Buffer Seal can be utilized in a variety of demanding hydraulic cylinders requiring superior reliability and lasting performance, which is particularly suited for earth moving and other mobile equipment applications. The product range consists of industry standard sizes to accommodate imperial (inch) dimensioned housings.

So, what’s the RBR buffer seal material?

Standard RBR Buffer Seal Materials

• P95T 95D … Polyurethane (Purple)
• NY46 … Nylon (Black)

Other material options may be available upon request.

Technical Specifications for the RBR Buffer Seal

Operating Condition

operating conditions of the blackhawk buffer seal

Featurespicture of blackhawk seals RBR buffer seal

  • Dual Element Design
  • Pressure Relieving
  • Excellent Extrusion Resistance
  • Excellent Wear Resistance
  • Zero Leakage Sealing System Performance
  • Low Compression Set
  • Low Friction
  • Easy Installation
  • Cost Effective
  • Robust Design

 

Cross Section3,000 psi3,000 psi5,000 psi7,500 psi
0.1250.0340.0280.0200.012
0.1870.0380.0300.0220.014
0.2500.0400.0320.0240.016
0.3120.0420.0340.0260.018
0.3750.0440.0360.0280.020
0.5000.0460.0380.0300.022

Maximum recommended diametrical extrusion gap when using precision wear rings.

 

Part NumberRod Dia. "d1" Tolerance h9Groove Dia. "D1" Tolerance H9Groove Width "L1" Tolerance +0/-0.010
RBR-12500250-125-P95T0.2500.5000.138
RBR-12500312-125-P95T0.31205.620.138
RBR-12500375-125-P95T0.3750.6250.138
RBR-12500437-125-P95T0.4370.6870.138
RBR-12500500-125-P95T0.5000.7500.138
RBR-12500625-125-P95T0.6280.8750.138
RBR-12500750-125-P95T0.7501.0000.138
RBR-12500875-125-P95T0.8751.1250.138
RBR-18700750-187-P95T0.7501.1250.205
RBR-18701000-187-P95T1.0001.3750.205
RBR-18701125-187-P95T1.1251.5000.205
RBR-18701250-187-P95T1.2501.6250.205
RBR-18701375-187-P95T1.3751.7500.205
RBR-18701500-187-P95T1.5001.8750.205
RBR-18701625-187-P95T1.6252.0000.205
RBR-18701750-187-P95T1.7502.1250.205
RBR-18701875-187-P95T1.8752.2500.205
RBR-25001500-250-P95T1.5002.0000.275
RBR-25001750-250-P95T1.7502.2500.275
RBR-25001875-250-P95T1.8752.3750.275
RBR-25002000-250-P95T2.0002.5000.275
RBR-25002125-250-P95T2.1252.6250.275
RBR-25002250-250-P95T2.2502.750.0275
RBR-25002375-250-P95T2.3752.8750.275
RBR-25002500-250-P95T2.5003.0000.275
RBR-25002625-250-P95T2.6253.1250.275
RBR-25002750-250-P95T2.7503.2500.275
RBR-25003000-250-P95T3.0003.5000.275
RBR-25003250-250-P95T3.2503.7500.275
RBR-25003500-250-P95T3.5004.0000.275
RBR-25003750-250-P95T3.7504.2500.275
RBR-25004250-250-P95T4.2504.7400.275
RBR-25005750-250-P95T5.7506.2500.275
RBR-31203500-312-P95T3.5004.125.03343
RBR-31203750-312-P95T3.7504.3750.343
RBR-31204000-312-P95T4.0004.6250.343
RBR-31204250-312-P95T4.2504.8750.343
RBR-31204500-312-P95T4.5005.1250.343
RBR-31204750-312-P95T4.7505.3750.343
RBR-37504750-375-P95T4.7505.5000.413
RBR-37505000-375-P95T5.0005.7500.413
RBR-37505500-375-P95T5.5006.2500.413
RBR-37505750-375-P95T5.7506.5000.413
RBR-37506000-375-P95T6.0006.7500.413
RBR-37506500-375-P95T6.5007.2500.413
RBR-37507000-375-P95T7.0007.7500.413
RBR-50007500-500-P95T7.5008.5000.550
RBR-50008000-500P95T8.0009.0000.550
RBR-50008500-500-P95T8.5009.5000.550
RBR50009000-500-P95T9.00010.0000.550
RBR50009500-500-P95T9.50010.5000.550
RBR50010000-500-P95T10.00011.0000.550

h9 and H9 tolerance per ISO 286. Additional sizes may be available.


Gallagher Fluid Seals is a preferred distributor of BlackHawk Seals. For more information about BlackHawk Seals, contact our engineering department or call 1-800-822-4063.