WIKA 910.17 Sealing Rings for Pressure Gauges and Accessories

WIKA 910.17 sealings for pressure gauges and instrument accessories

The WIKA 910.17 is a range of contact sealings for parallel thread connections on measuring instruments, valves, cocks, syphons, connection adapters and overpressure protectors. The data sheet lists three families: WIKA sealing rings, flat sealing rings per EN 837-1 (and similar), and edge sealing rings, in copper, aluminium, stainless steel 1.4571, nickel, steel, PTFE and asbestos-free Novapress 300 sealing material. Seven Star LLC supplies the 910.17 in Oman and the GCC as an independent supplier in Muscat, and this page explains the forms, materials and ordering information so the right ring is chosen for each thread.

How the 910.17 sealing works

A parallel (cylindrical) thread by itself cannot seal; the seal is made on the face between the stationary surfaces of the screw connection. When the prescribed tightening torque is reached, the sealing is pressed axially and the resulting surface pressure closes the joint. The sealing therefore prevents the accidental leakage of gaseous or liquid medium into the environment. WIKA recommends checking the sealing for damage or deformation at every disassembly and replacing it if necessary, which is simple advice with a large payoff: re-using a flattened copper ring is the most common cause of weeping gauge connections.

Design forms and centring of the 910.17

• Form 1: internal centring using a centring spigot per EN 837-1.
• Form 2: external centring in the threaded hole, for threaded spigots without centring spigot and without sealing lug.

The WIKA sealing has a special profile. After the connection has become tight, the part being aligned (a gauge, a valve) can be turned about one more rotation to reach the desired reading direction or operating position. For stainless steel WIKA sealings, which are stronger and have a specific form, high tightness is reached even at low tightening torque, but then the part can only be turned about half a further rotation. Traditional flat gaskets do not allow this, so the instrument ends up in the wrong position or the joint is not tight in the ideal position, and one needs to change gaskets of various thicknesses. The WIKA sealing avoids that unscrewing and re-fitting.

Technical specifications of the 910.17

Choosing the right ring material for the 910.17

Copper is the common choice for neutral media and moderate temperature. Aluminium suits low-load fittings. Stainless steel 1.4571 resists aggressive media and gives the high-pressure tightness described above. Nickel suits some chemical or higher temperature duty. Novapress 300 is the asbestos-free material for applications where metal rings would be too hard. PTFE flat rings are meant for diaphragm pressure gauges with threaded connections and for the “wetted parts from PTFE” option; the data sheet adds that if metal sealings are used there, the PTFE lining can be damaged. The 2.0 mm PTFE ring is mainly used on instruments and diaphragm seals for the food industry, where the wetted parts are generally stainless steel. Edge sealing rings come with solderless compression fittings and the ones listed here are mainly replacement parts.

Where the 910.17 fits and related WIKA products

The 910.17 sealings are used on the G 1/4 and G 1/2 male threads of gauges such as the 131.11, 213.40, 232.50 and PG23LT, and on transmitters with EN 837 connections such as the S-20. They are equally fitted at both ends of the stopcock 910.10, the shut-off valve 910.11, the snubber 910.12, the overpressure protector 910.13, the syphon 910.15 and the cooling element 910.32. A box of mixed rings is a very sensible spare for any instrument workshop.

Selection and ordering checklist for the 910.17

• Thread size: G 1/8, G 1/4, G 3/8, G 1/2 or M12 x 1.5, M20 x 1.5.
• Whether the fitting has a centring spigot (form 1) or not (form 2).
• Material: Cu, Al, 1.4571, Ni, NP uni or PTFE, matched to medium and temperature.
• Sealing family: WIKA sealing, flat sealing ring or edge sealing ring.
• Thickness for PTFE rings (0.5 mm or 2 mm).
• Quantity, since sealings are consumables.

Installation and replacement of the 910.17

Use a new sealing for every assembly. Clean both faces, place the sealing on the centring spigot or in the thread, and tighten to the required torque, using the spanner flats rather than the instrument case. With WIKA sealings, once the joint is tight, make the final alignment turn within the stated limit of about one rotation, or half a rotation for stainless steel. Do not stack two sealings to make up a gap. If a gauge continues to weep after replacing the ring, inspect the sealing faces for scoring and the thread for damage. Never use PTFE tape on the faces of a parallel thread sealing joint, since the seal is made on the face.

Typical applications in Oman and the GCC

Every plant with gauges, transmitters and valves in Oman needs a stock of sealing rings: compressed air and instrument air headers, fuel gas, cooling water, hydraulic units and steam utilities. The 910.17 is therefore a typical spares item for maintenance contractors serving oil and gas, power and desalination sites, often ordered together with gauges so that replacements fit the first time.

Sealing families at a glance

Information to send with an RFQ

• Model 910.17 with thread size and form
• Sealing family and material
• Quantity per size
• Medium and temperature
• Delivery site

Documents and quotation

The WIKA data sheet for the 910.17 is attached on this page with all sizes and order numbers.

Send the thread, material and quantity and Seven Star LLC will confirm availability and a quotation.