

BURKERT Type 2973 manually operated 2/2-way diaphragm valve. Features integrated locking, stroke limitation, and hygienic design for food, beverage, and pharma applications.

BURKERT Type 2973 manually operated diaphragm valve consists of a manually operated actuator, a diaphragm, and a 2-way body. The manual actuator with a plastic handwheel ensures use in hygienic or aggressive ambient conditions. The flow-optimized valve body with minimum dead space enables high flow values and a wide range of possible applications. The valve body and the diaphragms are available in all common materials and variants.
The actuator has a compact, autoclavable design and is compatible with all other Bürkert diaphragm valves. An explosion-proof ATEX/IECEx device variant is available. The manual actuator possesses a visual position indicator with a reproducible stroke scale. The actuator also possesses an adjustable minimum and maximum stroke limitation and/or locking. The manual actuator can be optionally equipped with sensors for position feedback.

| Product properties | Description |
|---|---|
| Forged steel valve body (VS) | Forged stainless steel 1.4435 in accordance with BN2 DIN EN 10222-5, F316L in accordance with ASTM A182/A182M and 316L in accordance with ASME BPE |
| Tube valve body (VP) | Stainless steel tube 1.4435-BN2 / UNS S31603 (316L) according to DIN 11866, ASTM A269 / A270, DIN EN 10217-7 / 10216-5 |
| Cast valve body (VG) | Stainless steel precision casting 1.4435 / 316L |
| Plastic valve body (PW, PV, PP, PD) | PVC-C, PVC-U, PP, PVDF |
| Diaphragm | EPDM (AD), PTFE/EPDM (EA), Advanced PTFE/EPDM (EU), laminate of GYLON® and EPDM (ER) |
| Actuator | Stainless steel/PPS (diaphragm bonnet/handwheel) |
| Diaphragm size | 15...50 |
| Operating medium | Neutral gases and liquids, highly purified, sterile, aggressive or abrasive mediums |
| Ambient temperature | -10...+130 °C (short-term up to +150 °C), autoclavable |

| No. | Element | Material |
|---|---|---|
| 1 | Lock pin | Stainless steel 1.4305 |
| 2 | Screw | Stainless steel A2 |
| 3 | Handwheel cover | Polyamide (PA) |
| 4 | Handwheel | Polyphenylene sulphide (PPS) |
| 5 | Visual position indicator | Polyamide (PA) |
| 6 | Valve spindle | Stainless steel 1.4305 |
| 7 | Diaphragm socket | Stainless steel 1.4308 |
| 8 | Diaphragm | EPDM (AD), PTFE/EPDM (EA), Advanced PTFE/EPDM (EU), Laminate of GYLON® and EPDM (ER) |
| Diaphragm size [mm] | Port connection [inch] | Kv value water [m³/h] (DIN EN ISO 1127) | Kv value water [m³/h] (ASME BPE) |
|---|---|---|---|
| 15 | 1/2 | 6.5 | 3.1 |
| 20 | 3/4 | 12.5 | 8.4 |
| 25 | 1 | 18 | 15.5 |
| 40 | 1 1/2 | 41 | 37 |
| 50 | 2 | 66 | 66 |
INFO
The K values may vary slightly for different diaphragm materials. Measurement at +20 °C, 4 bar at valve inlet and 3 bar at valve outlet.
| Diaphragm size | Maximum static operating pressure [bar] | Tightening torque EPDM, FKM [Nm] | Tightening torque PTFE/EPDM [Nm] |
|---|---|---|---|
| 15 | 10 | 0.8 | 1.7 |
| 20 | 10 | 0.9 | 3 |
| 25 | 10 | 1.2 | 3.5 |
| 32 | 10 | 2.5 | 4 |
| 40 | 10 | 4.5 | 7 |
| 50 | 10 | 6 | 11 |
WARNING
The tightening torques refer to the static media pressures specified above. Excessive torque can shorten the service life of the diaphragm. A tolerance of +10% applies to the tightening torques specified.
By manually overriding the handwheel, the force is transmitted via a spindle and the valve is opened or closed. Turning the handwheel anticlockwise opens the valve, turning it clockwise closes it.
Turning the handwheel counterclockwise reveals the yellow position indicator and the scale marked on it as the valve opens further. The scale on the handwheel determines the rotation position of the handwheel (Type 297x: 50 positions). The stroke scale shows the relative position of the valve and serves as a fixation point for determining the rotation position.

A minimum and maximum stroke limit can be set for Type 2973 (diaphragm sizes 15…50). An adjusting sleeve is used for this purpose.

For Type 2973 (diaphragm size 15…50), a locking mechanism is available as an option to prevent accidental or unauthorized operation. The locking pin has a bore (Ø 3.8) and can be secured against unauthorized use with a padlock.

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