Bürkert 20051147 is a Type 2101 pneumatically operated 2/2-way globe valve configured with a DN 40 orifice, 316L stainless steel body, and welded pipe ends conforming to ISO 4200, DIN 11866 Series B, and DIN EN ISO 1127. The line connection dimensions feature an outer diameter of 48.3 mm, an inner diameter of 44.3 mm, and a pipe wall thickness of 2.0 mm. Configured under control function B (normally open, CFB), the valve remains open in its unpressurized rest position via internal spring action and closes against the flow direction through pilot pressure applied to the actuator.

Operating across process pressures from 0 to 25 bar (PN 25, Class 150) and media temperatures between -10 °C and +185 °C, the unit delivers a nominal water flow coefficient (Kv) of 31 m³/h. The valve utilizes a screwed-in seat, a stainless steel swivel plate with PTFE seat sealing, and a polyphenylene sulphide (PPS) piston actuator. Certified compliant with Regulation (EC) 1935/2004 for food contact and suited for CIP and SIP processes, the valve handles neutral gases, steam, water, alcohols, fuels, hydraulic fluids, saline solutions, lyes, and organic solvents.

Structure and Functional Principles

Type 2101 valves consist of a pneumatically operated piston actuator coupled to a 2-way straight-seat body. A spindle connected to the internal actuator piston transmits opening and closing forces directly to the swivel plate assembly.

Control Function B and Seat Flow

Under control function B (CFB), the valve is held open in the resting position by spring force. Applying pilot air pressure to pilot port 1 forces the actuator piston downward to seal the swivel plate against the screwed-in valve seat.

The medium enters below the valve seat. Because the operating pressure acts beneath the swivel plate, process pressure aids valve opening and eliminates the pressure hammer risk inherent to flow-above-seat configurations on liquid lines.

Minimum Pilot Pressure and Leak Tightness

Insufficient pilot air pressure or operating pressures exceeding the permitted 25 bar limit can cause seat leakage under control function B. Always maintain pilot pressure within the specified 2.5 to 7.0 bar range.

Pressure and Temperature Operating Limits

The maximum permitted operating pressure depends on the medium temperature according to the applicable pipeline standard.

Temperature Range	Operating Pressure DIN EN 12516-1 (PN25)	Operating Pressure ASME B16.5 / B16.34 Cl. 150	Operating Pressure JIS B 2220 10K
-10 °C to +50 °C	25.0 bar	18.4 bar (at 50 °C) / 19.0 bar (-29 to 38 °C)	14.0 bar
+100 °C	24.5 bar	16.2 bar	14.0 bar
+150 °C	22.4 bar	14.8 bar	13.4 bar
+200 °C	20.3 bar	13.7 bar	12.4 bar
+230 °C	19.0 bar	12.7 bar	11.7 bar

Ambient Temperature Limits

Push-in pilot air connectors allow ambient operating temperatures between -10 °C and +60 °C. When combining the valve with electrical pilot valves or control tops, the maximum ambient temperature is limited to +55 °C.

Installation and Assembly

The valve may be installed in any physical orientation, preferably with the actuator oriented vertically upward. Ensure piping is accurately aligned and free of mechanical tension and debris before mounting.

Welded Body Installation

When installing valves with welded ends, the actuator assembly must be detached from the valve body before welding into the pipeline to prevent thermal damage to the internal seals and actuator casing.

1. Clamp the valve body in a vice or collet fixture.
2. Ensure the valve is open. For control function B, the valve is open in the unpressurized state.
3. Place an open-end wrench on the body connection hexagon and unscrew the actuator from the valve body.
4. Weld the body into the pipeline.
5. Check the body connection seal and lubricate the external threads using Klüberpaste UH1 96-402.

6. Screw the actuator back into the body while the valve is open. Tighten to the specified torque using an open-end wrench. Never use a pipe wrench.

Valve Body Connection Size	Body Tightening Torque
DN 15	45 ± 3 Nm
DN 20	50 ± 3 Nm
DN 25	60 ± 3 Nm
DN 32	65 ± 3 Nm
DN 40 (Bürkert 20051147)	65 ± 3 Nm
DN 50	70 ± 3 Nm
DN 65	100 ± 3 Nm
DN 80	120 ± 5 Nm
DN 100	150 ± 5 Nm

Actuator Orientation Adjustment

The actuator housing can be rotated 360° to optimize pilot air hose routing.

Rotation Direction

When turning the actuator, the valve must be in the open position. Rotate the actuator exclusively counterclockwise (as viewed from below). Turning clockwise risks loosening the body connection, leading to medium discharge under pressure.

Pneumatic Connections

Pilot air hoses measuring 6/4 mm or 1/4" connect directly into the push-in fitting at pilot port 1.

• Port 1: Connect control air supply (2.5 to 7.0 bar). Pressurizing closes the valve; venting opens the valve.
• Port 2: Exhaust port. Install the unattached silencer supplied with the unit to suppress exhaust air noise. In aggressive ambient atmospheres, route exhaust away via a pneumatic hose.

During ongoing operations, inspect the relief bore on the lower actuator neck regularly. Escaping process medium indicates wear of the spindle packing gland.

Maintenance and Replacement of Wearing Parts

Under standard industrial conditions, the actuator mechanism is maintenance-free. Natural wear is restricted to the PTFE swivel plate, the valve seat, and the spindle packing gland chevron rings.

Residual Pressure and Stored Spring Force

Before opening lines or disassembling the valve, depressurize the pipeline, drain all process media, and vent the pneumatic supply. Do not attempt to open the actuator housing; internal springs are under mechanical tension.

Replacing the Swivel Plate (Valve Set)

1. Remove the actuator from the valve body with the valve open.
2. Support the cylindrical portion of the swivel plate on a prism support.
3. Knock out the retaining pin using a suitable pin punch (ø 3 mm for 10 mm spindle, ø 5 mm for 14 mm spindle, ø 7 mm for 22 mm spindle).
4. Remove the worn swivel plate.
5. Fit the new swivel plate, align the boreholes, insert the new pin, and caulk both ends of the pin borehole with a punch.
6. Re-install the actuator into the valve body and torque to 65 ± 3 Nm.

Replacing the Screwed-in Valve Seat

1. Disassemble the actuator from the body.
2. Unscrew the damaged seat using the dedicated seat assembly tool and a wrench.
3. Clean the body threads and seal contact faces with compressed air.
4. Coat the external thread of the new seat with Klüberpaste UH1 96-402.
5. Thread the seat in by hand, then tighten with a torque wrench using the assembly tool.

Valve Seat Orifice Size	Coated Valve Seat Tightening Torque
DN 15	20 ± 3 Nm
DN 20	28 ± 3 Nm
DN 25	40 ± 5 Nm
DN 32	65 ± 5 Nm
DN 40 (Bürkert 20051147)	85 ± 8 Nm
DN 50	120 ± 8 Nm
DN 65	150 + 10 Nm
DN 80	180 + 10 Nm
DN 100	220 + 10 Nm

Replacing the Packing Gland

1. Remove the actuator and detach the swivel plate.
2. Unscrew the spindle guide using the modified socket wrench.
3. Eject the old packing elements by applying 6 to 8 bar pilot air to port 2 while safeguarding the spindle opening.
4. Grease the components of the replacement seal set and slide them onto the spindle in the exact orientation indicated in the assembly diagram.
5. Screw the spindle guide back in and tighten to the required torque:
   • 10 mm spindle diameter: 6 Nm
   • 14 mm spindle diameter: 15 Nm
   • 22 mm spindle diameter: 60 Nm

Replacement Parts and Ordering Information

Spare Part Set	Covered Size / Type	Order Number
Valve set (swivel plate with PTFE seal, pin, seal)	DN 40	011 209
Valve seat set (seat, O-ring, seal)	DN 40	262 177
Valve seat assembly tool	DN 40	652 608
Packing gland seal set (Standard variant)	DN 15–50 (actuator ø 50 / ø 70 mm)	216 433
Packing gland seal set (Water outlet up to 200 °C)	DN 15–50 (actuator ø 50 / ø 70 mm)	372 661
Packing gland seal set (High-temperature up to 230 °C)	DN 15–50 (actuator ø 50 / ø 70 mm)	372 662
Modified socket wrench for packing gland	Spindle ø 10 mm (AF 19)	683 221
Modified socket wrench for packing gland	Spindle ø 14 mm (AF 21)	683 223

Troubleshooting

Fault	Cause	Action
Actuator does not switch	Pilot air connections interchanged	For CFB, ensure pilot pressure is connected to port 1.
	Pilot pressure below 2.5 bar	Increase pilot pressure within 2.5 to 7.0 bar.
	Operating pressure above 25 bar	Verify system pressure conforms to type label.
	Medium flow direction inverted	Ensure arrow on body points in flow direction (below seat).
Valve seat leaks	Debris between seal and seat	Clean valve interior; install upstream strainer.
	PTFE seat seal worn or damaged	Install new swivel plate or valve set.
	Operating pressure too high	Reduce operating pressure below maximum limit.
	Pilot air pressure insufficient	Check pilot air supply and regulator.
Leakage at actuator relief bore	Spindle packing gland worn	Replace packing gland seal set.