The Burkert 20088504 Type 2960 control valve consists of a manual actuator and an angle seat valve body made of high-quality stainless steel. A parabolic cone enables a flow capacity that is up to 35% higher compared to conventional control valves. The precise spindle guide enables control, even under demanding operating conditions. A soft PTFE seal guarantees reliable sealing. The actuator is made of high-quality plastic (PPS) and is suitable for use in demanding environments. It possesses a visual position indicator and is 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.

Technical Data

• Design: Angle seat control valve
• Nominal Diameter: DN 50 (NPS 2)
• Flow Direction: Flow to open (below seat)
• Operating Pressure: 0 to 25 bar (PN 25 / Class 150)
• Seat Leakage: DIN EN 60534-4 Leakage class VI (PTFE)
• Kv Value (Water): 53 m³/h
• Operating Characteristic: Modified equal percentage (50:1)
• Operating Medium: Steam, water, neutral gases, alcohols, oils, fuels, hydraulic fluids, salt solutions, alkalis, organic solvents
• Medium Temperature: -10 °C to +130 °C
• Ambient Temperature: -10 °C to +60 °C
• Viscosity: Max. 600 mm²/s
• Port Connection: Clamp (ASME BPE / BS4825-3)
• Installation Position: As required, preferably with actuator upright

Materials

No.	Element	Material
1	Cover	Polyamide (PA)
2	Screw	Stainless steel 1.4301
3	Lock pin	Stainless steel 1.4305
4	Handwheel	Polyphenylene sulfide (PPS)
5	Optical position indicator with scale	Polyamide (PA)
6	Packing gland	PTFE V-rings (filled), with spring compensation
7	Spindle	Stainless steel 1.4401 or 1.4404
8	Spindle guide	Stainless steel 1.4404 (316L), PTFE filled
9	Body seal	Graphite
10	Control cone	1.4571 (optionally hardened)
11	Seat seal	PTFE
12	Valve body	Stainless steel 316L/CF3M

Design and Function

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. For the medium handwheel size (110 mm), the tightening torque must not exceed 15 Nm.

Position Indicator

When turning the handwheel anticlockwise, the reproducible stroke scale becomes visible between the position indicator and the handwheel. 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.

Note on Stroke Scale

The visibility of the stroke scale is not directly correlated with the closed position of the valve. Depending on the valve design, the repeatable stroke scale may not be visible when the valve is open, or be visible when the valve is closed.

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.

Installation and Adjustment

Risk of injury due to high pressure and escaping medium

Switch off the pressure before working on the device or system. Vent or drain the lines.

Risk of crushing by mechanically powered parts

Do not reach into the openings of the valve body.

Installing the Actuator

When screwing the actuator into the valve body for a DN 50 valve, observe a tightening torque of 70 Nm (±3 Nm). Grease the external thread of the body connection with an approved lubricant (e.g., Klüberpaste UH1 96-402) before assembly.

Setting the Stroke Limit

Setting the minimum and maximum stroke limit is possible via an adjusting sleeve.

1. By turning the handwheel clockwise, the valve is moved to the closed position.
2. Loosen the screw on the handwheel and remove it.
3. Screw the adjusting sleeve clockwise until it comes to a stop to set the minimum stroke.
4. Mount the handwheel, move the valve to the desired maximally open position, and remove the handwheel again.
5. Pull the adjusting sleeve upwards and at the same time, screw anticlockwise until it comes to a stop to set the maximum stroke.
6. Remount the handwheel and tighten the screw with a tightening torque of 0.9 Nm.

Locking the Handwheel

The handwheel can be locked to prevent unintentional or unauthorised operation. The medium handwheel size (110 mm) can be locked in 13 locking positions per revolution (every 27° corresponds to 0.13 mm of stroke).

Push the locking pin down and rotate by 180°. The locking pin has a bore (Ø 3.8 mm) and can be secured against unauthorised use with a padlock.

Servicing and Maintenance

When used in accordance with the operating instructions, the actuator of the manually operated valve is maintenance-free. Perform a visual inspection of the device once per year. If leaks occur, replace the respective wearing part. Muddy and abrasive media require correspondingly shorter inspection intervals.