GESTRA SMK 22-81 Sanitary Thermostatic Steam Trap PN 10

A sanitary thermostatic steam trap for clamp-connected sterile lines

The GESTRA SMK 22-81 is a thermostatic steam trap from the STERIline series, built for sterile and aseptic steam systems such as SIP and CIP duties in pharmaceutical, biotech, food and beverage plants. It has minimal stagnant area, a corrosion-resistant membrane regulator that is not affected by water hammer, and a rolling-ball valve cone that centres itself so that shut-off stays steam-tight even when dirt particles are present. The trap vents air automatically and discharges condensate without banking up over the whole pressure and temperature range, with an opening temperature of about 5 K below the boiling point.

The data sheet covers two types, SMK 22-81 and SMK 22-82, with clamp connections to DIN 32676 for pipes to DIN 11866 (DIN 11850, ISO 1127, ASME BPE).

Technical specifications

The first installation can use an accessory kit of two FDA-approved PTFE (FPM core) DIN 32676 D40 gaskets, two clamps and two end connections for orbital welding; other end connection sizes are available on request. Test certificates to EN 10204 2.2 and 3.1 are available at extra cost and must be stated with the order.

Using the trap on sterile steam lines

Fit the trap at low points and at the end of sterilisation steam lines, where condensate must leave without leaving a pool. Because it opens close to steam temperature, condensate does not stand in the line, which keeps sterilisation temperatures stable. The data sheet specifies a distance of 25 to 40 cm between the steam trap and the temperature measuring point, which is useful when a temperature sensor confirms the SIP cycle.

Two capacity curves are printed for each type: hot condensate that the trap discharges with virtually no banking up, and cold condensate at 20 C during start-up. Read both against the differential pressure of your line. Related steam equipment is listed under clean steam, for example the GESTRA UNA 16 ball float steam trap for general plant condensate.

How the GESTRA SMK 22-81 works

A thermostatic steam trap opens and closes according to the temperature of the fluid. In the SMK 22-81, a membrane regulator senses the temperature. Cold air and cold condensate keep the valve open, so they leave the line. When hot steam reaches the trap, the regulator expands and the rolling-ball cone closes against its seat. The trap opens about 5 K below the boiling point, so condensate leaves without banking up in the line. The cone centres itself, so shut-off stays tight even when small dirt particles are present, and the membrane is not damaged by water hammer.

Where the SMK 22-81 is used

• SIP and CIP lines in pharmaceutical and biotech plants.
• Sterile steam systems in food and beverage plants.
• Low points and line ends of sterilisation steam mains.
• Aseptic filling and process vessels.
• Clamp-connected hygienic pipework.

Selection checklist for the SMK 22-81

• Type: SMK 22-81 or SMK 22-82, as listed in the data sheet.
• Pressure rating of PN 10, with a maximum service pressure of 10 barg.
• Maximum differential pressure of 6 bar and a temperature up to 185 degrees C.
• Clamp connection to DIN 32676, and the pipe standard it matches.
• Body in 1.4404 stainless steel and a Hastelloy regulating capsule.
• PTFE gasket with an FPM core, FDA compliant.
• Surface finish of Ra 0.8 um, or the optional 0.6 um.
• Accessory kit with gaskets, clamps and orbital weld ends.
• Test certificate to EN 10204 2.2 or 3.1, which must be stated in the order.

Installation, commissioning and maintenance notes

Fit the trap at the lowest point of the line or at its end, where condensate collects, and keep the pipe slope toward the trap. Use the clamps and the gaskets of the correct size, and tighten the clamp evenly. Before first use, flush the line to remove welding debris. After installation, run a steam cycle and check the discharge. The data sheet describes the trap for sterile use, so follow the plant procedures for cleaning and sterilisation. Check the gasket at the planned interval and replace the trap element when the discharge is not correct.

Requesting a quotation for the GESTRA SMK 22-81

Send the type, the pipe size, the connection standard and whether you need the certificate. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

Minimal stagnant area

A trap with little dead volume holds less condensate, which helps to avoid places where microbes could grow in a sterile line.

Surface finish

The wetted parts are polished to Ra 0.8 um or better, which helps cleaning.

Weights and sizes

The functional unit is 35 to 65 mm long and weighs about 0.25 to 0.45 kg, so it fits small compact lines.

Steam trap records

Record the type, the installation point and the dates of each test.

Documents and quotation

The attached GESTRA data sheet 818919 provides ratings, materials, dimensions, spare parts and capacity charts. For a quotation please state the steam pressure, back pressure, condensate flow, type and size of end connections, and the application. Confirm the type (SMK 22-81 or SMK 22-82), connection standard and certificates before ordering.