Parker Fittings & Port Adapters

Parker pipe fitting shaped products (elbows, tees and crosses) are hot forged and machined. Parker straight pipe fittings are manufactured from cold drawn barstock. Where applicable, the fittings are made in conformance with SAE J514, J530. All Parker steel pipe fittings are zinc plated with silver chromate (zinc chromium 6 free). Stainless steel pipe fittings are passivated.

Related Information

• How Pipe Connections Seal
• Fitting Material Specs
• Technical Blog Posts
• Parker Tube Fittings Catalog (Parker Catalog 4300)
• See All Products

Application Guidelines
for Tapered Threads

Straight Connectors with NPT/NTPF Threads
3/4-14 and Smaller

Straight connectors with 3/4-14 NPT/NPTF and smaller male pipe threads have very high pressure holding capability and seal reliability when used in applications without need for disconnecting and reconnecting the fittings such as maintenance connections. They are also well suited for low cycle non-pulsating (static) applications with pressures in excess of 6,000 psi.

Straight Connectors with NPT/NPTF Threads Above 3/4 -14 and
All Shaped Connectors with NPT/NPTF Threads

It is difficult to always tighten shapes with pipe threads to an optimum tightness level because of orientation requirements.

Also, all connectors in with pipe threads have low reliability for leak free operation in dynamic applications. Therefore, they are not preferred where a leak free joint is required.

All NPTF Connectors

Pipe thread connections can be disassembled and reassembled in low-pressure systems, but they are not intended to be a frequently assembled and disassembled. For connections in higher pressure systems requiring frequent disassembly and reassembly, use connections with an elastomeric seal, such as SAE straight thread port (SAE J1926/ISO11926), SAE four bolt split flange (SAE J518/ISO 6162), or ISO 6149. For applications where elastomeric seals can’t be used, please contact our customer service.

BSPT & Metric Taper Connections

BSPT and metric taper connections are similar to the NPT/NPTF connections. Follow the same guidelines.

All tapered thread connections have the following limitations:

• Poor dynamic sealing
• Possible expansion/cracking of the port
• Orientation is a concern with shaped connectors
• Larger threads are more prone to leakage (more potential leak points)
• System contamination by thread sealants
• Prone to galling, especially in stainless steel
• Limited remakeability