GESTRA TK 23 Duo Super Steam Trap PN 16, DN 50-100

A pilot-controlled steam trap for large continuous condensate flows

The GESTRA TK 23 is a Duo Super steam trap with thermostatic pilot control for high condensate capacities. Corrosion-resistant thermostatic capsules, unaffected by water hammer, open and close the trap just below the pressure-dependent saturation temperature. The trap vents air and other non-condensable gases automatically at start-up and in operation, so it suits large continuous condensate flows such as heat exchangers, main drains, large heaters and process equipment, and it is also used for air venting of pipelines. An external adjustment device can limit the main valve lift or hold a minimum condensate flow.

The data sheet covers TK 23 (cast iron body, PN 16) and TK 24 (cast steel body, PN 25) in DN 50 to 100 mm (2 to 4 inch). The 50 mm size has three thermostatic capsules; sizes 65 to 100 mm have four.

Technical specifications

Differential pressure is inlet pressure minus outlet pressure. With 0 H 2 capsules the maximum operating pressure is only 5 bar.

Selecting TK 23 or TK 24

Use TK 23 for low-pressure steam up to 13 barg and TK 24 where operating pressure reaches 21 barg. Size the trap on the condensate load at your actual differential pressure with the capacity chart in the data sheet, and choose the standard 5 H 2 capsule unless the differential pressure is below 1 bar, where 0 H 2 capsules are used. Cast bodies and large flanged sizes suit permanent plant installations rather than portable equipment.

Make sure the flow arrow on the body matches the flow direction, because a trap installed against the arrow will malfunction, and avoid insulating the trap or condensate line so that the trap can dissipate heat. Related items are listed under steam and clean steam equipment, for example the GESTRA UNA 16.

How the GESTRA TK 23 works

A steam trap must let condensate out but keep steam in. The TK 23 uses thermostatic capsules that are filled with a liquid. When hot steam reaches them, the liquid expands and closes the valve. When condensate cools slightly below the saturation temperature, the capsules contract and open it. A pilot control moves a larger main valve, so the trap can pass a large flow through a compact body. The capsules vent air and other gases at start-up, so the plant warms up faster and without air pockets.

Where the TK 23 is used

• Heat exchangers and large heaters.
• Main steam drains.
• Process equipment with large continuous condensate flows.
• Air venting of steam pipelines.
• Dryers, evaporators and tracing headers.

Selection checklist for the TK 23

• TK 23 with cast iron body PN 16, or TK 24 with cast steel body PN 25.
• Size: DN 50, 65, 80 or 100.
• Maximum operating pressure of 13 barg for the TK 23 and 21 barg for the TK 24.
• Maximum allowable temperature of 300 degrees C or 400 degrees C.
• Capsule 5 H 2 for a differential pressure of 1 to 10 bar, or 0 H 2 for up to 5 bar.
• Flanges to DIN PN 16 or PN 25, and ANSI drilling on request.
• Face-to-face length of 230, 290, 310 or 350 mm.
• Weight of 16 to 43 kg for the TK 23.
• Adjustment device for limiting the lift or holding a minimum flow.

Installation, commissioning and maintenance notes

Install the trap at the lowest point of the drain with the flow in the direction of the arrow, and fit a strainer and isolation valves around it. Flush the pipe before start-up, since scale and weld debris damage any trap. Support the pipe so that the trap does not carry the load. Check the trap regularly for blow-through and for flooding, using a suitable test method, and replace the capsules at the interval your inspection suggests. Keep a record of each trap in the steam trap survey.

Requesting a quotation for the GESTRA TK 23

Send the size, the operating pressure and the condensate flow. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

Materials

The TK 23 body is cast iron GG-25, while the TK 24 body is cast steel, and the capsule has a Hastelloy membrane with stainless steel parts and asbestos-free gaskets.

Water hammer

The capsules are not affected by water hammer, and the trap opens and closes just below the saturation temperature.

Flange data

The flange diameter runs from 165 to 220 mm for the TK 23, depending on the nominal size.

Trap records

Record the tag, the size and the test results of each trap.

Strainers and test points for the TK 23

A strainer ahead of the trap and a test point after it make the survey of the trap easier and protect the capsules from dirt.

Insulation

Do not insulate the capsule cover more than the data sheet allows, because the trap needs to lose a little heat to work as intended.

Documents and quotation

The attached GESTRA data sheet 818540 gives ratings, materials, dimensions, weights and capacity charts. For a quotation send the steam pressure, differential pressure, condensate flow, nominal size and flange standard, and confirm the type and capsule before ordering.