Hydraulic system downtime often starts with a simple mistake: misidentifying a fitting. Mixing a Tapered Pipe Thread (NPT) with a Flare Seal (JIC) is a guaranteed failure. Field service technicians need a rapid, reliable process for hydraulic fitting identification without relying solely on memory.
? Step 1: Determine the Thread Type (Parallel or Tapered)
This is the most critical step. Use a caliper and check the thread diameter at the start and the end of the threads.
Tapered Threads (NPT/NPTF): The thread diameter gets progressively smaller towards the end. These require pipe dope or PTFE tape to seal.
Parallel Threads (JIC, ORFS, BSPP): The thread diameter remains constant from start to end. These rely on a separate mechanism (flares, O-rings, or bonded seals) for the zero-leak sealing.
? Step 2: Measure the Thread Angle (37°, 60°, or Not Applicable)
Once you confirm the threads are parallel, you must identify the sealing angle:
JIC (Joint Industry Council): Uses a distinct 37-degree flare surface. This is a metal-to-metal seal.
BSP (British Standard Pipe): Often uses a 60-degree cone but relies on a crush washer or bonded seal.
ORFS (O-Ring Face Seal): Has a flat face; the thread is purely for retention. The seal is handled by the O-ring on the face.
?️ Step 3: Check the Sealing Mechanism (O-Ring or Metal)
Feel the sealing surface to confirm the presence of a groove:
O-Ring: If there is a machined groove for an O-ring on the thread or the face (ORB or ORFS), the fitting is designed for zero-leak sealing reliability.
Metal Seating: If the threads are tapered or if a 37-degree flare is present, the seal relies on precise metal contact.
Are you constantly battling a mix of old and new fittings?
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