Locking screw, Hexagonal socket, without flange, R 1/4 - Riegler 137939

Locking screw, Hexagonal socket, without flange, R 1/4 nickel-plated brass Max. working pressure 25 bar Max. operating temp.150 °C Suitable for air, water, oil, steam, etc.

Standards and origin

• Customs tariff number: 74122000
• Country of origin: GR

About Caps and Screw plugs

Locking screws and end caps close off unused ports on manifolds, valve blocks and fittings. That allows a plant to be built with spare ports without leaking at the open bore. Threads run from M5 up to G 2 at working pressures of 20 to 60 bar.

What matters when choosing

• The thread follows the port being closed. Parallel G threads are available from G 1/8 to G 2, plus tapered R threads in R 1/8 and R 1/4 and M5 for small bores.
• The thread standard determines where the joint seals. Parallel threads to DIN EN ISO 228-1 need a seal at the shoulder, tapered threads to ISO 7-1 seal in the thread itself.
• For the seal, NBR covers general service. FDA-compliant FPM is chosen where food contact or higher temperatures are involved.
• Material follows the surroundings. Brass CW614N and electroplated nickel-plated brass CW614N for normal use, stainless steel 1.4571 and 1.4404 for corrosive media and cleaning routines.
• Pressure and temperature limit the choice. Working pressure reaches 60 bar, maximum operating temperature is either 80 °C or 150 °C depending on the version.

Typical applications

• Closing unused outlets on compressed air manifolds and valve terminal base plates
• Blanking off ports on air preparation units and cylinders that will be used later
• Sealing test and measuring ports once a pressure test is finished
• Plugging spare ports on hydraulic and oil line blocks
• Securing ports in cleaning and food areas using the FDA-compliant FPM seal

The NonPlusUltra versions are made from stainless steel 1.4404 and sealed with FDA-compliant FPM, released for compressed air, neutral gases and liquids, oil and grease. The value line series is also part of the group, which holds 253 articles.