Swagelok SS-810-1-OR O-Seal Male Connector, 1/2 in. Tube

Hydraulic ports and many pump, valve and manifold bodies use straight SAE/MS threads sealed by an O-ring rather than tapered pipe threads. The Swagelok SS-810-1-OR is the O-seal male connector for that port: a 1/2 in. Swagelok tube end joined to a 3/4-16 UNF straight male thread with a Buna N O-ring, in 316 stainless steel.

Technical specifications

How an O-seal port works

A tapered NPT thread seals by deformation and needs sealant. A straight-thread port seals at an O-ring, which sits in a groove and is compressed against a flat or spot-faced surface when the hex is tightened. The thread only provides the clamping force. This gives repeatable sealing in hydraulic and lubrication circuits and avoids the problems that sealant can cause in fine filters and control valves. The catalog states that O-seal fittings include a 70 durometer Buna N O-ring and that other O-ring materials are available on request.

The 3/4-16 thread size is the SAE/MS size matched to a 1/2 in. tube in the catalog table, and the hex flat of 1 1/8 in. is larger than the 7/8 in. on the NPT male connector.

Installation of O-seal connectors

The catalog instructions for O-seal male connectors are simple: check that the factory-lubricated O-ring is intact (the catalog says O-rings are coated with a thin silicone-based lubricant), thread the connector in by hand until it seats, then tighten until it makes metal-to-metal contact with the face of the port, and finish with a slight wrench tightening. The tube end is then installed in the normal way, with one and one-quarter turns of the nut for the 1/2 in. size.

Check the port: O-seal ports need a smooth sealing face and a correct thread. Damaged faces, burrs or the wrong thread standard (for example ISO parallel) will leak. If your port is ISO/BSP, use the RS or RP versions of the Swagelok male connector.

Decoding and options

SS-810-1-OR: SS is 316 stainless, 810 the 1/2 in. tube, 1 the male connector and OR the O-seal thread, with the thread size implied by the tube size. NPT versions of O-seal fittings carry a size block between the tube and OR, as in SS-810-1-8-OR, which uses the O-seal on a pipe thread. Positionable straight-thread elbows and tees use ST designators. The catalog shows pressure ratings for SAE/MS thread sizes in its ST table; check the table for your thread size and material.

Seven Star LLC supplies these fittings by exact part number; check that the mating port is SAE/MS 3/4-16 and not a metric or ISO parallel thread before ordering.

Selection checks before ordering SS-810-1-OR

Three questions decide whether this connector is right. First, is the port really an SAE/MS straight thread of the 3/4-16 size? Measure the thread pitch and diameter with a gauge rather than judging by eye, because several parallel thread standards look similar. Second, does the tubing match: 1/2 in. outside diameter, in a material and wall thickness that suit the system pressure and the Swagelok tube fitting? Third, is the O-ring material compatible with the fluid and the temperature of the circuit? The page lists Buna N as standard; if the system carries a fluid that is not compatible with it, raise this before ordering so the correct option can be discussed.

Assembly practice on site

Keep the fitting in its packaging until it is needed, so the O-ring and threads stay free of sand and grit. Before installation, inspect the port face for scratches, paint or old sealant, and clean it with a lint-free cloth. Do not add PTFE tape or thread sealant to a straight-thread O-seal port; the seal is made by the O-ring, and tape fragments can end up in valves and filters downstream.

Cut the tube square, deburr it, and make sure it is fully bottomed in the fitting before the nut is tightened. Follow the Swagelok installation instructions to confirm that the tube end has been made up correctly. Support the tube close to the fitting so that pipe weight and vibration are not carried by the connection.

Commissioning and leak testing

After assembly, pressure-test the circuit according to the site procedure, increasing pressure in stages and inspecting each joint. A weep at the port usually points to a damaged O-ring, an unsuitable sealing face or a thread mismatch, so stop, depressurise and investigate rather than simply tightening further. Record the test pressure and result on the job sheet.

Hydraulic and process systems in Oman and the GCC

Hydraulic power units, lubrication skids and instrument panels in the Gulf often operate in hot, dusty surroundings. High ambient temperature raises fluid temperature, which should be checked against the O-ring limits for the chosen material. Wind-blown sand can enter open ports during maintenance, so cap any open fitting or tube end straight away. At coastal and offshore sites, salt-laden air is a concern for all external tubing; 316 stainless steel is widely used in these settings, but keep fittings clean and include them in the plant inspection routine.

Maintenance

When a connection is broken for maintenance, inspect the O-ring before reuse and replace it if it shows cuts, flattening or hardening. Remake the tube end following the Swagelok reassembly instructions for the size.

Documents and quotation

Download the official Swagelok catalog MS-01-140 from this page for the full ordering tables. Requests for SS-810-1-OR are quoted against the exact order code, so include quantity and any cleaning or packaging option.

Check the code, size and end connection against the catalog table before purchase, since variants with similar numbers exist. Related items: product category.