Burkert Type 2961 control valve consists of a manual actuator and a globe valve body with exchangeable seats made of high-quality stainless steel. Each globe valve body can be equipped with up to 8 valve seat sizes and reaches the desired flow characteristic curve in interaction with parabolic cones. The precise spindle guide enables control, even under demanding operating conditions. A soft PTFE or PEEK seal guarantees reliable sealing. The actuator is made of high-quality plastic and is suitable for use in demanding environments. It possesses a visual position indicator and can be optionally equipped with stroke limitation and locking. The packing gland uses tried-and-tested V-seals and possesses spring compensation, which means that it does not need to be pulled back manually.

Product Features

• Position indicator: When turning the handwheel counterclockwise, the reproducible stroke scale becomes visible between the attachment and the handwheel. The scale on the handwheel, together with the stroke scale, enables reproducible adjustment of the flow rate.
• Interlock (optional): The valve can be secured against unintentional or unauthorized operation. For this purpose, a securing pin can be pressed down and turned. The locking pin has a hole (∅ 3.8) and can be secured with a padlock.
• Stroke limitation (optional): Both the minimum and the maximum position of the valve can be adjusted via an adjustment sleeve. The handwheel can be removed for this purpose.

Position Indicator Note

The scale on the handwheel determines the rotation position of the handwheel (50 positions). The reproducible stroke scale shows, depending on the bottom edge of the handwheel, the relative position of the valve (valve opening) and acts as a fixation point for determining the rotation position.

Materials

No.	Element	Material
1	Cover	Polyamide (PA)
2	Screw	Stainless steel 1.4301
3	Locking device	Stainless steel 1.4305
4	Handwheel	Polyphenylene sulphide (PPS)
5	Visual position indicator with scale	Polyamide (PA)
6	Packing gland	PTFE V-rings (filled), with spring compensation
7	Stem	Stainless steel 1.4401 or 1.4404
8	Spindle guide	Stainless steel 1.4404 (316L), PTFE filled
9	Housing seal	Graphite
10	Control cone	1.4571 (optionally hardened)
11	Seat seal (optional)	PTFE or PEEK
12	Valve seat with O-ring	Stainless steel 1.4571, EPDM
13	Valve body	Stainless steel 316L/CF3M

Technical Data

Operating Conditions

Parameter	Value
Media	Neutral gases, water, alcohols, oils, fuels, saline solutions, lyes, organic solvents, vapour
Ambient temperature	-10...+60 °C
Medium temperature	-40...+230 °C (depending on seal material)
Storage temperature	-20...+65 °C
Temperature for valve seat seal	for a medium temperature of up to 130 °C: PTFE for a medium temperature of over 130 °C: PEEK / steel

Operating Limits for Seat Seal

Tight sealing required	Leakage class (DIN EN 60534 - 4)	Medium temperature	Seat seal
No (An additional shut-off valve is recommended)	II (metal seals)	-40 °C...+230 °C	Stainless steel
Yes (An additional shut-off valve is often unnecessary)	VI (soft seals)	-40 °C...+130 °C (recommended for ≤ +130 °C)	PTFE
Yes	VI (soft seals)	-10 °C...+230 °C (recommended for > +130 °C)	PEEK

Dimensions

Actuator Dimensions

Nominal connection size [DN]	Nominal connection size [NPS]	Handwheel diameter ∅ [mm]	H1 [mm]	H2 (locking) [mm]
15	1/2	45 (S)	217	224
20	3/4	45 (S)	224	230
25	1	45 (S)	228	234
32	1 1/4	110 (M)	296	303
40	1 1/2	110 (M)	301	307
50	2	110 (M)	307	313
65	2 1/2	160 (L)	361	368
80	3	160 (L)	369	375
100	4	160 (L)	379	385

Installation

Installation Safety

• Switch off the pressure before working on the device or system. Vent or drain the lines.
• Do not reach into the openings of the valve body.
• Ensure a controlled restart after installation.

Flow Direction

The valve seat is always closed against the medium flow. The flow direction should therefore be set such that the valve reaches the flow beneath the valve seat.

Set Stroke Limit

Setting the minimum and maximum stroke limit is possible as an option. An adjusting sleeve is used for this purpose.

1. By turning the handwheel clockwise, the valve is moved to the closed position.
2. Loosen the screw on the handwheel (hexagon socket, width across flats 2) and remove handwheel.
3. Screw adjusting sleeve clockwise until it comes to a stop. Minimum stroke is set.
4. Mount handwheel on actuator. The square on the spindle and the hexagon head of the adjusting sleeve must be correctly aligned.
5. Move the valve to the desired maximally open position.
6. Loosen the screw on the handwheel and remove the handwheel.
7. Pull adjusting sleeve upwards and at the same time, screw anticlockwise until it comes to a stop. Maximum stroke is set.
8. Mount handwheel on actuator and tighten the screw with a tightening torque of 0.9 Nm.

Lock Handwheel

It is also an option to lock the handwheel to prevent unintentional or unauthorised operation of the valve.

• Handwheel size S can be locked in 12 locking positions per revolution.
• Handwheel sizes M and L can be locked in 13 locking positions per revolution.

Push locking pin down and rotate by 180° (either clockwise or anticlockwise). Insert padlock through the bore in the locking pin and secure.

Explosion Protection (ATEX)

For devices with Ex approval (e.g., PX51: EPS 18 ATEX 2008 X / IECEx EPS 18.0007 X mech. Ex h IIC T4…T2 Gb / Ex h IIIC T135 °C…T300 °C Db), the following applies for use in Zones 1/21 and 2/22:

Danger of Explosion from Electrostatic Charge

If a statically charged device or person suddenly discharges, there is a risk of explosion in the potentially explosive area.

• Take appropriate measures to ensure that no electrostatic charge can build up in the potentially explosive area.
• Only wipe the surface of the device gently with a damp or anti-static cloth.
• Ground the actuator and the valve body.
• If a plastic valve body is used, ground the actuator separately.

Device Grounding

1. Ground the valve body: To establish equipotential bonding, ground the valve body to the piping system using a conductive connection.
2. Ground conductive components: Conductive parts must be grounded separately. To do this, install a grounding strap clip or grounding terminal (if not pre-installed) as shown below and ground it via a grounding point.