WIKA TW61 Sanitary Protection Tube for Orbital Welding

WIKA TW61 sanitary protection tube for orbital welding

The WIKA TW61 is a protection tube for hygienic process lines. It is orbitally welded straight into a pipeline and is used to adapt a TR21-B miniature resistance thermometer or a TR22-B resistance thermometer to the process while protecting the sensor from harsh conditions. The design is patented by the manufacturer, is self-draining and keeps dead space to a minimum, and it is made from materials and surface finishes that follow hygienic design standards. Seven Star LLC supplies the TW61 in Oman and the GCC as an independent supplier in Muscat; the sections below describe the versions, the nominal widths and the information needed to order the right tube.

What the TW61 does in a sanitary line

In food, beverage, biotech and pharmaceutical plants the temperature point must not trap product or cleaning fluid. The TW61 is welded into the pipe as a flow-through housing or an angular housing, so the sensor sits in the line without a conventional thermowell stub. The measuring insert can be withdrawn together with the connection head, which makes on-site calibration of the full measuring chain possible without disconnecting the electrical wiring. The process stays closed during this step, so the risk of contamination is reduced. With a TR22-B thermometer the swivel connection of the head or display can be loosened and rotated to the preferred direction.

Technical specifications of the TW61

Pipe sizes covered by the TW61

The data sheet tabulates the tube for three pipe standards, with a tube length, a protection tube insertion length U1 and neck tube lengths that depend on the nominal size. A short excerpt shows the principle.

The same table lists neck tube lengths: for example DN 25 row A uses 39 mm for the TR21-B and 117 mm for the TR22-B, while DN 80 uses 12 mm and 90 mm. Row A covers DN 10 to DN 100, row B covers DN 8 to DN 80 in ISO tube sizes, and row C covers ½ in to 4 in ASME BPE tube. Nominal pressure in the table is 25 bar up to DN 50 on row A, reducing to 16 bar for DN 65 and DN 80 and 12.5 bar for DN 100; for ASME tube the table states 13.8 bar on every size.

Hygienic details: sealing combination and BVS head

The optional sealing combination at the neck tube is made of polyurethane and consists of a flat gasket and a wiper. It prevents moisture and impurities from entering and settling at the transition from the connection head to the tube, achieves IP68 and makes cleaning much simpler. Combined with the patented BVS head and a cable gland in hygienic design, the whole measuring point can be cleaned easily because cleaning agents run off the case without residues collecting.

Compatible thermometers and related models

The TW61 is intended for the TR21-B miniature resistance thermometer (data sheet TE 60.27) and the TR22-B resistance thermometer (TE 60.23), both for orbital welding. For general industrial lines the weld-in TW20 or TW25, or the threaded TW15 and TW45, are the relevant alternatives. A sanitary clamp-connection thermowell is a different family, so check the connection type before ordering.

Selection and ordering checklist for the TW61

• Pipe standard (row A metric, row B ISO or row C ASME BPE) and nominal size.
• Housing: flow-through or angular.
• Thermometer: TR21-B (G 3/8) or TR22-B (M24 x 1.5).
• Material 1.4435 or 316L, and the surface roughness class including electropolishing.
• Neck tube length matched to the thermometer insertion length.
• Sealing combination at the neck tube, yes or no.
• Approvals and certificates required by the plant.

Installation and commissioning of the TW61

Orbital welding is performed by qualified personnel using the plant welding procedure, and the connection ends are supplied smooth and prepared for that process. After welding, inspect the weld seam and the interior, then install the thermometer. Because the measuring insert can be removed with the head, calibration can be done on site, and the manufacturer notes the 150 mm and 125 mm lengths are suitable for its dry-well calibrator. Clean-in-place and steam-out procedures should respect the 150 °C medium temperature limit.

Typical applications in Oman and the GCC

Dairy, juice and beverage bottling, bakery and food processing, pharmaceutical production, water-for-injection loops and biotech facilities in Oman and the GCC need clean temperature points. The TW61 serves these hygienic lines, and also CIP skids on larger industrial sites where the temperature probe must not create a dead leg.

Information to send with an RFQ for the TW61

• Pipe standard, nominal size and wall thickness.
• Housing form and thermometer model (TR21-B or TR22-B).
• Material, surface finish and electropolishing.
• Neck tube length and sealing combination.
• Medium and temperature, quantity and delivery location.

Documents and quotation

The WIKA data sheet TW 95.61 for the TW61 is attached on this page. Send your pipe specification and we will respond as an independent supplier in Muscat, making no claim of an official WIKA relationship.