BURKERT 20093947 (Type 2100) is a pneumatically operated 2/2-way angle seat valve designed for decentralized process automation in sanitary, chemical, and hygienic process lines. Featuring a flow-optimized cast stainless steel CF3M body, this variant is manufactured with ASME BPE / DIN 11866 Series C weld ends in nominal size DN 20 (3/4"). Operating under Control Function A (normally closed by spring force), the valve uses a 50 mm (size D) pneumatic piston actuator that routes flow under the valve seat, eliminating water hammer when handling liquid media while maintaining tight shut-off on clean steam, gases, and corrosive process fluids.

Construction and Component Identification

Item	Description	Item	Description
1	Transparent cap with position indicator	7	Port connection (ASME BPE weld end)
2	Actuator cover (PPS)	8	Body connection nut
3	Actuator housing (Stainless steel 1.4561)	9	Actuator connection
4	Relief bore (spindle gland leak indicator)	10	Pilot air port 1
5	Valve body (Stainless steel CF3M)	11	Pilot air port 2 (exhaust/vent)
6	Flow direction arrow marking

Principle of Operation and Flow Direction

Burkert 20093947 operates using Control Function A (CFA). In its de-energized rest state, mechanical spring force pushes the actuator piston downward, seating the PTFE seal plate tightly against the orifice to close the valve. When pilot air of at least 5.2 bar(g) enters pilot air port 1, it overcomes the spring force, retracting the spindle and lifting the swivel plate into the full open position.

The flow path is configured below the seat (flow-to-open). Because process pressure acts on the underside of the swivel plate, line pressure assists in opening the valve. This flow configuration is required for liquid applications to prevent rapid deceleration and pressure surges (water hammer). It is fully qualified for liquid media, saturated steam, and technical gases.

Flow and Pressure Parameters

• Circuit Function: 2/2-way normally closed (NC, CFA)
• Flow Direction: Below seat
• Seat Diameter: 20 mm
• Water Flow Factor (Kv): 8.4 m³/h (measured with water at +20 °C at 1 bar pressure differential across the valve)
• Operating Pressure Range: 0 to 16 bar(g)
• Minimum Pilot Pressure: 5.2 bar(g) (maximum pilot limit: 10 bar(g))

Materials of Construction

Wetted surfaces are constructed from austenitic stainless steel and fluoropolymer compounds certified to Regulation (EC) 1935/2004 for food contact and compatibility with Clean-in-Place (CIP) and Sterilize-in-Place (SIP) thermal regimes. Spindle sealing is achieved using self-adjusting PTFE V-rings preloaded with packing springs and lubricated with NSF H1 compliant grease.

Item	Component	Standard Material Specification
1	Ground terminal	Stainless steel 1.4301 / 1.4305 (included on ATEX-certified variants)
2	Optical position indicator	Polysulfone (PSU)
3	Pilot air port	Polypropylene (PP) push-in connector (G 1/8" stainless steel 1.4305 on request)
4	Actuator cover	Polyphenylene sulphide (PPS)
5	Actuator casing	Stainless steel 1.4561 (316Ti)
6	Piston seal	Fluorocarbon elastomer (FKM)
7	Actuator spring	Stainless spring steel 1.4310
8	Tube / Actuator neck	Stainless steel 1.4401 (316) / 1.4404 (316L)
9	Spindle packing gland	PTFE V-rings (carbon-filled), spring-compensated
10	Valve spindle	Stainless steel 1.4401 (316) / 1.4404 (316L)
11	Spindle guide	Polyetheretherketone (PEEK)
12	Body seal	Graphite (PTFE optional)
13	Swivel plate	Stainless steel 1.4401 (316) / 1.4404 (316L)
14	Seat seal	PTFE (Polytetrafluoroethylene)
15	Valve body	Cast stainless steel CF3M (equivalent to AISI 316L)

Dimensions and Installation Geometry

Welded Connection Dimensions (ASME BPE / DIN 11866 Series C)

Size (NPS)	Size (DN)	Insertion Depth ES [mm]	Port Height CS [mm]	Length LS [mm]	Outer Diameter ∅ DS [mm]	Wall Thickness WS [mm]
1/2"	DN 15	30	46	135	12.70	1.65
3/4"	DN 20 (20093947)	30	52	145	19.05	1.65
1"	DN 25	30	51	152	25.40	1.65
1 1/2"	DN 40	30	60	182	38.10	1.65
2"	DN 50	30	64	210	50.80	1.65
2 1/2"	DN 65	26	56	230	63.50	1.65
3"	DN 80	26	88.5	266	76.20	1.65

Actuator Envelopes and Automation Head Heights

Actuator Size	Actuator ∅ A [mm]	Base Actuator B [mm]	Base Actuator H [mm]	Centerline Clearance K/M [mm]	Height with Type 8690 / 8697 [mm]	Height with Type 8691 / 8695 [mm]
50 (D) – DN 20	64.5	174	171	155	234	247
70 (M) – DN 20	91.0	189	186	163	240	264

Note: Dimensions B, H, K, and M are maximum values and can decrease by up to 6 mm depending on weld pipe tolerances.

Temperature and Pressure Limits

The operating boundary of Burkert 20093947 is determined jointly by the mechanical rating of the CF3M valve body and the thermal limits of the pneumatic pilot connections.

Pressure Derating per ASME B16.34 Class 150 & DIN EN 12516-1 PN 25

Temperature [°C]	Class 150 Limit [bar(g)]	PN 25 Limit [bar(g)]	Article 20093947 Operating Limit [bar(g)]
-29 to +38	19.0	25.0	16.0
+50	18.4	25.0	16.0
+100	16.2	24.5	16.0
+150	14.8	22.4	14.8
+185	13.9	20.9	13.9
+200	13.7	20.3	Not permitted (variant limit +185 °C)

Ambient vs. Medium Temperature Operating Envelopes

• Push-in pilot connector (standard): Permissible medium temperature -10 °C to +185 °C with ambient temperature from -10 °C to +60 °C.
• Threaded pilot port G 1/8" (optional): Permissible medium temperature -10 °C to +185 °C with ambient temperature up to +100 °C.
• Mounted automation modules (Type 8690 / 8691 / 8695 / 8697): Observe the specific ambient limit stated in the accessory operating instructions (typically -10 °C to +55 °C).

Mechanical Installation and Welding

Welded Connection Notice

Never weld a valve body into a pipeline while the actuator mechanism is attached. Radiant and conductive welding heat will destroy the internal PTFE seat seal, spindle packing rings, and FKM actuator seals.

Disassembly Prior to Welding

1. Clamp the CF3M valve body securely in a vice or pipe fixture.
2. Apply 5.0 to 5.2 bar compressed air to pilot air port 1 to retract the valve into the open position. Attempting to unscrew the body connection while the valve is closed under spring tension will score or distort the PTFE swivel plate.
3. Apply an open-end wrench to the body connection wrench flats (position 8).
4. Unscrew the complete actuator assembly counterclockwise from the body.

Pipeline Welding and Reassembly

1. Check pipeline alignment and remove metal shavings, scale, and contaminants from the tube bore.
2. Weld the valve body into the pipeline according to ASME BPE orbital or manual TIG specifications.
3. Allow the welded joints and valve body to cool completely to ambient room temperature.
4. Check the integrity and seating position of the body gasket seal.
5. Apply a light film of food-grade lubricant (such as Klüberpaste UH1 96-402) to the threads of the body connection.
6. Pressurize pilot air port 1 with 5 bar air to hold the spindle in the open position.
7. Thread the actuator assembly clockwise into the body. Tighten to the specified torque:

Nominal Valve Size	Actuator Size	Tightening Torque [Nm]	Tolerance [Nm]
DN 15	40 (C), 50 (D), 63 (E)	45	+10 / -5
DN 20 (20093947)	50 (D), 70 (M)	50	+10 / -5
DN 25	50 (D), 63 (E), 80 (F)	60	+10 / -5
DN 32	63 (E), 80 (F), 100 (G)	65	+10 / -5
DN 40	63 (E), 80 (F), 100 (G), 125 (H)	65	+10 / -5
DN 50	70 (M), 90 (N), 130 (P)	70	+10 / -5

Rotating the Actuator for Cable / Hose Routing

The actuator assembly rotates 360° continuously to facilitate clean routing of pneumatic hoses and electrical cabling.

Actuator Rotation Precaution

Pressurize pilot air port 1 with 5 bar compressed air to open the valve before turning the actuator. Hold the body connection hexagon with a fixed counter-wrench and turn the actuator hex nut only in the direction indicated in the figure. Turning in the reverse direction loosens the body connection and causes process fluid leakage.

Pneumatic Setup

1. Verify pilot air quality conforms to dry, filtered instrument air free of abrasive residues or corrosive chemical vapors.
2. Insert 6 mm outer diameter semi-rigid pneumatic tubing into pilot air port 1 until fully seated in the push-in fitting.
3. Pilot port 2 functions as a spring chamber breather on single-acting Control Function A valves. Install the included porous silencer into port 2 to prevent ambient dust from being drawn into the cylinder.
4. In washdown or chemically aggressive plant atmospheres, connect a vent hose to port 2 and route the exhaust into a neutral, clean atmosphere.

Maintenance and Troubleshooting

Inspection Checklist

Inspection Point	Observed Fault	Corrective Action
Port connections (1)	External pipe joint leakage	Re-weld joint or replace flange/clamp gaskets
Relief bore (2)	Fluid leaking from actuator neck bore	Packing gland worn; replace packing set or replace actuator assembly
Valve seat (3)	Internal bypass / seat leakage	Swivel plate worn or contaminated; clean seat or install new swivel plate

Operational Faults and Remediation

Symptom	Probable Cause	Remedial Action
Actuator does not stroke	Supply line connected to wrong port	Connect control pressure directly to pilot air port 1
	Pilot pressure below 5.2 bar(g)	Increase pilot supply pressure to 5.2–10 bar(g) range
	Operating line pressure exceeds 16 bar(g)	Verify process pressure complies with valve rating
Valve seat bypass leakage	Particulate matter lodged in orifice	Dismantle actuator and flush pipeline / clean seating surface
	Worn or scored PTFE seat seal	Replace swivel plate assembly using spare kit
	Fluid flow inverted	Check flow arrow on body; ensure medium enters under the seat
Continuous leak at relief bore	Spindle packing V-rings worn	Replace packing gland using installation tool (AF 19 mm, article 683221)

Service Tool Information

Replacement of the internal spindle packing gland requires the dedicated Bürkert packing gland socket wrench. For DN 20 valves with a 10 mm spindle diameter, use socket wrench AF 19 mm (Bürkert Article No. 683221).