BURKERT 20067288 (Type 2100) is a pneumatically operated 2/2-way angle seat valve belonging to the ELEMENT series, engineered for decentralized process automation in industrial gas and vapour applications. Featuring a DN20 nominal diameter, G 3/4 female threaded ports, and an installation length of 75 mm, the valve combines a CF3M cast stainless steel body with a polyphenylene sulphide (PPS) actuator and stainless steel connection components.

The self-adjusting PTFE V-ring packing gland with spring compensation ensures stem seal integrity over extended operating cycles. Operating with control function A (normally closed by spring force), this valve variant is designed with media flow directed above the valve seat, allowing operating pressure up to 16 bar and delivering a water flow coefficient (Kv) of 11 m³/h. The device meets ingress protection ratings IP67 and NEMA 4X, and qualifies for CIP and SIP sanitization procedures.

Operating Principle and Flow Direction

In control function A (CFA), internal spring tension acts through the spindle directly on the stainless steel swivel plate to maintain the valve in a normally closed state without pilot pressure. Applying compressed air to pilot air port 1 lifts the piston and spindle against the spring mechanism, opening the flow path.

Model 20067288 is configured specifically for medium flow above the seat. In this arrangement, line pressure acts on the top of the swivel plate, contributing to the sealing force when the valve is closed.

Restricted Media for Flow Above Seat

Valves with flow direction above the seat must be used exclusively for gaseous media and vapours. Do not use this valve configuration for liquid media, because rapid closing against liquid flow causes severe pressure surges (water hammer) that can burst pipelines and destroy the valve body.

Technical Data and Operational Limits

Operational limits vary according to medium temperature, pilot pressure, and applicable piping standards.

Parameter	Value
Orifice / Nominal Size	DN20 (20 mm)
Fluidic Connection	G 3/4 female thread
Installation Length	75 mm
Flow Direction	Above seat
Control Function	A (normally closed)
Operating Pressure Range	0 to 16 bar
Pilot Pressure Range	2.7 to 10 bar
Kv Value (Water)	11 m³/h
Ambient Temperature (Push-in connector)	-10 °C to +60 °C
Ambient Temperature (Threaded bushing)	-10 °C to +100 °C
Medium Temperature (PTFE seal)	-10 °C to +200 °C
Storage Temperature	-20 °C to +65 °C
Protection Class	IP67 (EN 60529 / IEC 60529), NEMA 4X
Sound Pressure Level	< 70 dB(A)

Temperature and Pressure Derating

Maximum allowable operating pressure decreases at elevated medium temperatures. The table below details derating values across standards:

Temperature [°C]	DIN EN 12516-1 / PN25 [bar]	ASME B16.34 Cl. 150 [bar]	JIS B 2220 10K [bar]
-10 to +38 / +50	25.0	19.0	14.0
100	24.5	16.2	14.0
150	22.4	14.8	13.4
200	20.3	13.7	12.4
230	19.0	12.7	11.7

Mechanical Assembly and Installation

Prior to mounting in the pipeline, ensure pipe sections are precisely aligned and free of weld spatter, burrs, and foreign particulate. Installations complying with DIN EN 161 (automatic shut-off valves for gas burners) require a strainer upstream that prevents the passage of a 1 mm mandrel.

Actuator Dismantling and Reassembly

When removing or reinstalling the actuator housing on the valve body, the valve must be held in the open position to protect the PTFE seat seal and internal drive spindle from torsional stress.

Pneumatic Actuation Required Before Disassembly

For valves with control function A, pressurise pilot air port 1 with compressed air at 5 bar to open the valve before unscrewing the body connection. Failure to open the valve before loosening can damage internal sealing components.

1. Secure the valve body in a holding fixture.
2. Apply 5 bar compressed air to pilot air port 1 to fully retract the swivel plate.
3. Fit an open-end wrench across the wrench flat of the body connection.
4. Unscrew the actuator assembly from the valve body.

When reassembling, inspect the body seal for damage and lubricate the thread of the body connection (using Klüber paste UH1 96-402 or an equivalent medium-compatible lubricant). Apply 5 bar pilot air to port 1, thread the actuator assembly into the body, and tighten according to the specified torque:

Nominal Diameter	Actuator Size	Tightening Torque [Nm]	Tolerance [Nm]
DN15	40 (C), 50 (D), 63 (E)	45	+10 / -5
DN20	40 (C), 50 (D), 63 (E), 80 (F)	50	+10 / -5
DN25	50 (D), 63 (E), 80 (F)	60	+10 / -5
DN32	63 (E), 80 (F), 100 (G)	65	+10 / -5
DN40	63 (E), 80 (F), 100 (G), 125 (H)	65	+10 / -5
DN50	63 (E), 70 (M), 80 (F), 90 (N), 100 (G), 125 (H)	70	+10 / -5

Turning the Actuator Orientation

The actuator housing can be rotated 360° to align pilot air ports with plant pneumatic lines.

Rotational Alignment Procedure

1. Secure the valve body in a vice or holding fixture.
2. Pressurise pilot air port 1 with 5 bar compressed air to lift the swivel plate off the valve seat.
3. Hold the hexagon nut on the body connection with a stationary open-end wrench.
4. Place a second open-end wrench on the hexagon nut of the actuator connection.
5. Turn the actuator nut only in the direction indicated in the figure until the required port orientation is reached.

Pneumatic Connection and Commissioning

Pneumatic pilot air must be supplied via neutral gases or clean compressed air using 6 mm external diameter hoses connected to the push-in fittings.

• Pilot Air Port 1: Connect the control air signal here. Applying pilot pressure opens the normally closed valve.
• Pilot Air Port 2: Serves as the actuator exhaust port. Install the supplied silencer into port 2. In corrosive or harsh ambient atmospheres, pipe port 2 to a clean, neutral environment using a pneumatic hose.

Commissioning Steps

1. Check that pilot pressure is set within the specified range (minimum 2.7 bar, maximum 10 bar) and conforms to values on the type label.
2. Pressurise the device with pneumatic pilot air first to establish controlled valve positioning.
3. Slowly introduce the process medium into the pipeline.
4. Verify that pipeline operating pressures do not exceed 16 bar, and adhere to temperature derating curves.

Maintenance and Troubleshooting

Routine inspection requires monitoring three primary functional locations for external or internal leakage.

Inspection Point	Observed Condition	Corrective Action
Media connectors (1)	Medium leaking at pipe joints	Re-tighten threaded joints or replace piping seals
Relief bore (2)	Medium or air escaping through relief hole	Replace spindle packing gland or replace complete actuator
Swivel plate / seat (3)	Internal seat leakage in closed position	Replace valve seat set (swivel plate) and inspect for debris

Troubleshooting Guide

Problem	Possible Cause	Corrective Action
Actuator does not switch	Pilot air connected to wrong port	Connect control pressure supply to pilot air port 1
	Pilot pressure insufficient	Increase pilot pressure according to type label specifications
	Operating pressure exceeds limit	Reduce operating pressure below maximum rating (16 bar)
	Flow direction reversed	Align pipe flow with direction marked on valve body
Valve seat is not tight	Particulates lodged between seat and seal	Flush pipeline or install an upstream strainer
	PTFE swivel plate worn	Replace swivel plate assembly
Leakage at relief bore	Spindle packing gland damaged or worn	Replace packing gland using dedicated socket tool

Service Accessories

Replacement of the internal spindle packing gland requires the dedicated socket wrench:

Spindle ∅ [mm]	Nominal Diameter DN	Width Across Flats [mm]	Article Number
10	15 to 50	19	683221
14	32 to 80	21	683223