BURKERT 378793 (Type 2100) is a pneumatically operated 2/2-way ELEMENT angle seat valve configured for on/off shut-off duty in demanding process environments. Engineered with control function A (normally closed by spring force), this valve features DN 25 weld ends conforming to ISO 4200, DIN EN ISO 1127, and DIN 11866 series B. The wetted valve body is cast from stainless steel CF3M and equipped with a PTFE seat seal, delivering a water flow coefficient Kv of 20 m³/h across an operating pressure range of 0 bar to 16 bar. As a dedicated oxygen variant, article 378793 is assembled with parts free of oil and grease per Burkert standard DIS 1000020797, suitable for gaseous oxygen up to 60 °C, and fully qualified for Clean-in-Place (CIP) and Steam-in-Place (SIP) routines.

Technical Data for Article 378793

Parameter	Value
Article Number	378793
Valve Type	Type 2100 ELEMENT
Construction	Complete valve unit
Switching Positions / Ports	2/2-way
Control Function	CF A (normally closed by spring force)
Flow Direction	Below seat (flow to open)
Port Connection Type	Weld end
Port Size	DN 25 (1")
Pipe Standards	ISO 4200 / DIN EN ISO 1127 / DIN 11866 series B
Pipe External Diameter (∅ DS)	33.7 mm
Pipe Wall Thickness (WS)	2.0 mm
Pipe Internal Diameter	29.7 mm
Installation Length (LS)	130 mm
Nominal Pressure Class	PN 25 (DIN EN 1333) / Class 150 (DIN EN 1759)
Operating Pressure Range	0.00...16.00 bar(g)
Minimum Pilot Pressure	4.8 bar(g)
Maximum Pilot Pressure	10.0 bar(g)
Flow Rate Kv (Water at +20 °C)	20 m³/h
Seat Diameter	25 mm
Medium Temperature Range	-10 °C...+60 °C (oxygen service limitation)
Ambient Temperature Range	-10 °C...+60 °C (push-in connector limitation)
Valve Body Material	Stainless steel CF3M (cast 316L)
Seat Seal Material	PTFE (polytetrafluoroethylene)
Swivel Plate Material	Stainless steel 1.4401 / 1.4404 (316 / 316L)
Actuator Size	Ø 70 mm (size M)
Actuator Cover Material	PPS (polyphenylene sulphide)
Actuator Casing Material	Stainless steel 1.4561 (316Ti)
Pilot Air Interface	Push-in connector external Ø 6 mm (ELEMENT interface)
Manual Override	None
Vacuum Variant	No
Oxygen Variant	Yes (NL02)
Cleanliness Standard	Free of oil and grease per DIS 1000020797
CIP / SIP Capability	Yes / Yes
Ingress Protection	IP65/IP67, NEMA Type 4X

Operating Principle and Flow Direction

Article 378793 uses pilot air at 4.8 bar(g) to 10 bar(g) admitted through pilot air port 1 to lift the actuator piston against internal spring force, lifting the spindle and opening the PTFE seat seal. When control air is vented, the spring force forces the swivel plate down onto the valve seat to restore the closed position.

Media flows underneath the seat (flow direction below seat). Because media pressure acts below the swivel plate, line pressure assists in opening the valve. This flow-to-open orientation prevents water hammer when controlling liquids.

Flow Direction Safety Limit

Do not install valves configured with flow direction above the seat in liquid media lines. Pressure surges and water hammer will cause pipes and valve components to burst. Flow direction below seat as configured on article 378793 is mandatory for liquid handling.

Material Specifications

Type 2100 valves incorporate a self-adjusting PTFE V-ring packing gland with spring compensation to maintain spindle sealing integrity without manual retightening. Lubricants for the packing gland and actuator are certified according to NSF H1.

No.	Component	Material
1	Ground terminal	Stainless steel 1.4301 / 1.4305 (included on ATEX variants)
2	Optical position indicator	Polysulfone (PSU)
3	Pilot air ports	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	FKM
7	Spring	Stainless steel 1.4310
8	Pipe	Stainless steel 1.4401 (316) / 1.4404 (316L)
9	Packing gland	Filled PTFE V-rings, spring-compensated
10	Spindle	Stainless steel 1.4401 (316) / 1.4404 (316L)
11	Spindle guide	PEEK
12	Body seal	Graphite (PTFE optional)
13	Swivel plate	Stainless steel 1.4401 (316) / 1.4404 (316L)
14	Seat seal	PTFE (PEEK optional)
15	Valve body	Stainless steel CF3M

Dimensions

Article 378793 combines a DN 25 welded body with a 70 mm (M) actuator. Dimensions below apply to the standard unit and assemblies with ELEMENT control heads.

Welded Body Dimensions (ISO 4200 / DIN EN ISO 1127 / DIN 11866 Series B)

Nominal Diameter	Pipe Outer ∅ DS [mm]	Wall Thickness WS [mm]	End Length ES [mm]	Port Center Height CS [mm]	Installation Length LS [mm]
DN 10	17.2	1.6	20	34	100
DN 15	21.3	1.6	19	34	100
DN 20	26.9	1.6	20	39	115
DN 25	33.7	2.0	26	43	130
DN 32	42.4	2.0	26	45	145
DN 40	48.3	2.0	26	49	160
DN 50	60.3	2.0	26	50	175
DN 65	76.1	2.3	26	50	210
DN 80	88.9	2.3	26	88.5	266

Actuator and Overall Assembly Dimensions

For DN 25 paired with actuator size 70 mm (M):

• Actuator diameter (∅ A): 91 mm
• Centerline to actuator top (B): 191 mm max.
• Centerline to optical indicator top (H): 188 mm max.
• Centerline to pilot port axis (K/M): 165 mm max.
• Height with mounted Type 8690 or Type 8697 pneumatic control unit: 242 mm
• Height with mounted Type 8691 or Type 8695 control head: 266 mm

Operating Limits and Derating

Although the mechanical body rating complies with PN 25 (DIN EN 1333) and Class 150 (DIN EN 1759), the maximum operating pressure of article 378793 is 16 bar(g). Operating pressure is subject to thermal derating according to DIN EN 12516-1.

Temperature [°C]	Maximum Pressure PN 25 (DIN EN 12516-1) [bar]	Class 150 (ASME B16.34) [bar]	Article 378793 Permissible Limit [bar(g)]
-10...+50	25.0	18.4	16.0
+60	24.8	17.5	16.0
+100	24.5	16.2	Not permitted for oxygen variant
+150	22.4	14.8	Not permitted for oxygen variant
+200	20.3	13.7	Not permitted for oxygen variant

Oxygen Service and Temperature Limitations

Non-metallic wetted components in article 378793 comply with oxygen suitability requirements up to 25 bar(g) and medium temperatures up to +60 °C. The push-in pilot air connectors limit ambient operating temperature to -10 °C...+60 °C. Do not operate article 378793 above +60 °C in oxygen installations.

Installation and Assembly Guidelines

Type 2100 valves can be installed in any orientation, preferably with the actuator upright.

Welding Procedure

Before welding the valve body into the piping network, always unscrew the pneumatic actuator from the body to protect internal seals and guiding elements from heat distortion. Apply 5 bar compressed air to pilot air port 1 to open the valve before unscrewing. Reassemble only when the body has cooled completely.

Body Connection Tightening Torques

When reinstalling the actuator onto the valve body, tighten the body hexagon to the specified torque:

Nominal Diameter DN	Compatible Actuator Sizes	Tightening Torque [Nm]	Tolerance [Nm]
15	40 (C), 50 (D), 63 (E)	45	+10 / -5
20	40 (C), 50 (D), 63 (E), 80 (F)	50	+10 / -5
25	50 (D), 63 (E), 70 (M), 80 (F)	60	+10 / -5
32	63 (E), 80 (F), 100 (G)	65	+10 / -5
40	63 (E), 80 (F), 100 (G), 125 (H)	65	+10 / -5
50	63 (E), 70 (M), 80 (F), 90 (N), 100 (G), 125 (H)	70	+10 / -5
65	80 (F), 100 (G), 125 (H)	70	+10 / -5
80	125 (H), 130 (P)	120	+10 / -5

Actuator Orientation

The actuator housing can be rotated continuously through 360° to optimize pilot air hose routing. Pressurize pilot air port 1 with 5 bar compressed air to open the valve before rotating the actuator connection with an open-end wrench.

Maintenance and Inspection

Type 2100 requires periodic visual inspection for external tightness and seat sealing integrity.

Inspection Zone	Observed Issue	Corrective Action
Media connectors (1)	Flange/weld pipeline leakage	Retighten connection or re-weld joint
Relief bore (2)	Medium or air escaping from relief hole	Replace spindle packing gland or actuator assembly
Valve seat (3)	Internal leakage across seat	Replace swivel plate and PTFE seat seal set

For packing gland service on DN 15 to DN 50 valves (spindle diameter 10 mm), use Bürkert special installation socket wrench tool article no. 683221 (width across flats 19 mm).

Automation and Modular Combinations

Article 378793 integrates with Burkert ELEMENT control tops to establish complete automated valve assemblies (System Type 8801-YE):

• Type 8690: Pneumatic control unit with mechanical or inductive end position switches for actuator size Ø 70 mm.
• Type 8691: Control head with contact-free inductive position sensor, coloured high-performance LEDs, and integrated pilot valve.
• Type 8695: Compact control head with integrated pilot valve, teach-in function, and AS-Interface / IO-Link / büS communications.
• Type 8697: Compact pneumatic feedback unit with optical position indicator and optional ATEX/IECEx intrinsic safety.