BURKERT 338166 (Type 2100) is a pneumatically operated 2/2-way angle seat valve belonging to the ELEMENT platform, engineered for hygienic and process industrial service. Configured under article number 338166, the assembly features a DN 15 nominal port size with ASME BPE clamp connections, an installation face-to-face length of 130 mm, an actuator size of 70 mm (size code M), and Control Function A (normally closed by internal spring force). Fluid enters below the seat (flow-to-open), eliminating hydraulic pressure surges when closing against liquid media.

The flow-optimized cast stainless steel body (CF3M) achieves a flow coefficient Kv of 1.6 m³/h with water. Sealing integrity at the seat is maintained by a virgin PTFE seal ring, meeting Leakage Class A per DIN EN 12266-1 under operating pressures up to 25 bar(g). The spindle is guided by PEEK bushings and sealed with a self-adjusting PTFE V-ring packing gland incorporating spring compensation, preventing stem leakage across repeated thermal cycles from -10 °C to +185 °C. The valve is CIP and SIP capable and complies with EC Regulation 1935/2004.

Control Functions and Flow Direction Rules

Type 2100 angle seat valves are built in multiple operating functions across single-acting and double-acting configurations:

• Control Function A (CF A): Pneumatically operated 2/2-way shut-off valve, closed by spring force in the rest position (NC). Pilot air applied to pilot port 1 lifts the piston against the spring pack to open the valve orifice.
• Control Function B (CF B): Pneumatically operated 2/2-way shut-off valve, opened by spring force in the rest position (NO). Pilot pressure introduced into pilot port 1 overcomes spring force to drive the seal against the seat.
• Control Function I (CF I): Pneumatically operated 2/2-way valve with double-acting actuator piston. Rest position is unpressurized and undefined; pressurizing port 1 opens the orifice, while pressurizing port 2 closes it.

Flow Direction and Water Hammer Restrictions

When using liquid media, fluid must always flow below the seat (flow to open). In the case of liquid mediums, flow above the seat generates severe hydraulic water hammer during closing, which can burst process pipelines, fittings, and the valve body. Never install valves with flow above the seat on liquid services.

Flow direction below the seat introduces line pressure beneath the swivel plate, assisting valve opening upon pilot actuation. Flow direction above the seat is reserved strictly for compressible gases and clean steam, where line pressure assists seat tightness in normally closed (CF A) configurations.

Materials of Construction

Wetted and structural components utilize corrosion-resistant metallurgy and engineering polymers. Factory lubricants applied to the packing gland and pneumatic actuator are certified according to NSF H1.

Item	Component	Material Specification
1	Ground terminal	Stainless steel 1.4301 / 1.4305 (supplied for ATEX variants)
2	Optical position indicator	Polysulfone (PSU)
3	Pilot air ports	Polypropylene PP push-in connector (Standard); G 1/8" 1.4305 stainless steel on request
4	Actuator cover	Polyphenylene sulphide (PPS)
5	Actuator casing	Stainless steel 1.4561 (316Ti)
6	Piston seal	Fluoroelastomer (FKM)
7	Spring pack	Stainless steel 1.4310
8	Actuator pipe	Stainless steel 1.4401 (316) / 1.4404 (316L)
9	Packing gland	PTFE V-rings (filled), spring-compensated
10	Spindle	Stainless steel 1.4401 (316) / 1.4404 (316L)
11	Spindle guide	Polyether ether ketone (PEEK)
12	Body seal	Graphite (PTFE optional)
13	Swivel plate	Stainless steel 1.4401 (316) / 1.4404 (316L)
14	Seat seal	Virgin PTFE (PEEK optional)
15	Valve body	Cast stainless steel CF3M (316L equivalent)

Fluidic Performance and Operating Data

Fluidic performance for welded and clamp connections complying with ASME BPE / DIN 11866 series C with media flowing below the seat:

Nominal Diameter DN	NPS	Seat Size DN [mm]	Actuator Size Ø [mm]	Kv Water [m³/h]	Min. Pilot Pressure [bar(g)]	Max. Operating Pressure CFA PTFE [bar(g)]	Max. Operating Pressure CFA PEEK [bar(g)]	Max. Operating Pressure CFB PTFE [bar(g)]
15	1/2"	15	50 (D)	1.6	5.2	25.0	25.0	25.0
15	1/2"	15	70 (M)	1.6	4.8	25.0	25.0	25.0
20	3/4"	20	50 (D)	8.4	5.2	16.0	13.5	25.0
20	3/4"	20	70 (M)	9.4	4.8	25.0	25.0	25.0
25	1"	25	50 (D)	13.0	5.2	9.0	—	25.0
25	1"	25	70 (M)	16.0	4.8	16.0	13.5	25.0
25	1"	25	90 (N)	16.0	5.0	25.0	25.0	25.0
40	1 1/2"	40	70 (M)	35.0	4.8	6.0	—	25.0
40	1 1/2"	40	90 (N)	38.0	5.0	16.0	13.5	25.0
40	1 1/2"	40	130 (P)	41.0	5.0	25.0	23.0	25.0
50	2"	50	70 (M)	49.0	4.8	4.0	—	16.0
50	2"	50	90 (N)	55.0	5.0	10.0	8.0	25.0 (20.0 *)
50	2"	50	130 (P)	58.0	5.0	25.0 (20.0 *)	23.0 (20.0 *)	25.0 (20.0 *)
65	2 1/2"	65	90 (N)	85.0	5.0	5.0	—	14.0
65	2 1/2"	65	130 (P)	85.0	5.6	16.0 (15.0 *)	12.5	16.0 (15.0 *)
80	3"	65	90 (N)	91.0	5.0	5.0	—	14.0
80	3"	65	130 (P)	91.0	5.6	16.0 (15.0 *)	12.5	16.0 (15.0 *)
80	3"	80	130 (P)	140.0	5.6	10.0	8.0	11.0

* Pressure reduction per Pressure Equipment Directive 2014/68/EU for compressible fluids of group 1 (dangerous gases and vapors).

Pressure and Temperature Operating Limits

Maximum working pressure decreases at elevated medium temperatures according to international piping codes.

Pressure Derating According to Pressure Standards

Temperature [°C]	DIN EN 12516-1 / PN 25 [bar]	ASME B16.34 Cl. 150 [bar]	JIS B 2220 10K [bar]
-29 to +38	25.0	19.0	14.0
-10 to +50	25.0	18.4	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

Ambient and Medium Temperature Operating Range

Pilot Air Port Type	Medium Temperature Range (PTFE / PEEK)	Permissible Ambient Temperature Range
Push-in connector (external Ø 6 mm or 1/4")	-10 °C to +230 °C	-10 °C to +60 °C
Threaded metal bushing (G 1/8")	-10 °C to +230 °C	-10 °C to +100 °C
Mounted control head (Type 8691 / 8695 / 8690 / 8697)	-10 °C to +185 °C	-10 °C to +55 °C

Dimensions and Installation Interface

Valve Body Dimensions for Clamp ASME BPE (DIN 11866 Series C)

NPS	DN	Overall Length LC [mm]	Body Center Height CC [mm]	Clamp Flange Ø D1 C [mm]	Tube OD Ø D2 C [mm]	Wall Thickness SC [mm]
1/2"	15	130	49.0	25.0	12.70	1.65
3/4"	20	150	56.5	25.0	19.05	1.65
1"	25	160	58.0	50.5	25.40	1.65
1 1/2"	40	200	69.0	50.5	38.10	1.65
2"	50	230	77.5	64.0	50.80	1.65

Actuator Envelope Dimensions

Actuator Size Code	Actuator Housing Ø A [mm]	Total Height B [mm]	Axis Height H [mm]	Centerline Clearance K/M [mm]
50 (D)	64.5	166	163	147
70 (M)	91.0	182	178	156
90 (N)	120.0	229	228	203
130 (P)	159.0	293	293	254

Dimensions B, H, K, and M represent maximum envelope values and may measure up to 6 mm less depending on the specific body port size and standard.

Installation and Actuator Mounting

Pipe systems must be clean, free from welding slag or debris, and properly aligned before clamping. For gas installations certified to DIN EN 161, a dirt trap with a maximum mesh opening preventing the passage of a 1.0 mm mandrel must be installed upstream.

Pneumatic Actuation Required During Actuator Servicing

To avoid damaging the valve seat seal and spindle mechanism during actuator installation or removal, the valve must be held in the fully open position. For normally closed valves (Control Function A), apply 5.0 bar(g) of clean compressed air to pilot air port 1 before loosening or tightening the body connection.

Body Connection Tightening Torques

When reinstalling the actuator onto the stainless steel valve body, inspect the body seal ring, apply food-grade thread paste (such as Klüber paste UH1 96-402), and tighten to the specified torque:

Nominal Diameter DN	Actuator Sizes Covered	Specified Tightening Torque [Nm]	Permissible Tolerance [Nm]
15	40 (C), 50 (D), 63 (E), 70 (M)	45	+10 / -5
20	40 (C), 50 (D), 63 (E), 70 (M), 80 (F)	50	+10 / -5
25	50 (D), 63 (E), 70 (M), 80 (F)	60	+10 / -5
32	63 (E), 70 (M), 80 (F), 90 (N), 100 (G)	65	+10 / -5
40	63 (E), 70 (M), 80 (F), 90 (N), 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), 90 (N), 100 (G), 125 (H), 130 (P)	70	+10 / -5
65	175 (K), 225 (L)	100	+10 / -5
80	125 (H), 130 (P)	120	+10 / -5
100	125 (H), 175 (K), 225 (L)	150	+10 / -5

360° Actuator Rotational Alignment

The pneumatic pilot ports can be positioned through 360° to accommodate tubing runs. Clamp the valve body firmly, pressurize pilot port 1 with 5 bar compressed air to open the valve orifice, and use an open-end wrench on the hexagon flat of the actuator drive connection. Hold the body connection stationary and rotate the actuator drive connection in the indicated tightening direction only to reach the desired alignment.

Pneumatic Connection Guidelines

Pneumatic pilot hoses require a 6 mm or 1/4" outer diameter. For push-in connections, a silencer is supplied loose to diminish exhaust velocity and noise; thread the silencer into free exhaust port 2. In corrosive or aggressive washdown areas, duct exhaust lines away into a neutral atmosphere.

Maintenance and Troubleshooting

Regularly verify tight shut-off and external integrity during operation:

Inspection Point	Observed Condition	Corrective Maintenance Action
Media connectors (1)	Flange clamp leaking	Re-align pipeline, verify gasket integrity, re-tighten clamp
Relief bore (2)	Process fluid weeping	Replace PTFE packing gland or complete actuator assembly
Swivel plate (3)	Internal seat bypass	Replace swivel plate assembly / seat seal ring

Special socket wrenches are used to replace the stem packing gland cartridge without damaging internal guide surfaces:

• Article 683221: 19 mm socket width for 10 mm spindle diameter (covers DN 15 through DN 50).
• Article 683223: 21 mm socket width for 14 mm spindle diameter (covers DN 32 through DN 80).

Troubleshooting Guide

Fault Condition	Probable Root Cause	Corrective Action
Actuator fails to stroke	Pilot connections inverted	Connect pilot pressure line to port 1 for CF A and CF B valves
	Pilot air pressure below rating	Verify pilot pressure satisfies minimum threshold (min. 4.8 bar for size 70)
	Line pressure exceeds limit	Check process operating pressure against nameplate maximum
	Reversed line installation	Verify medium flow arrow on valve casting matches pipeline flow direction
Seat leakage in closed position	Pilot pressure low (CF B / CF I)	Raise pilot air supply to match pressure diagrams
	Particulate under seat	Install upstream line strainer to block pipe scale
	Seat seal worn or damaged	Install replacement swivel plate kit
Leakage through relief bore	Packing gland V-rings worn	Replace stem packing gland assembly using socket wrench tool

Hazardous Area Requirements (ATEX / IECEx)

When ordered with ATEX / IECEx mechanical certification (codes PX51 / II 2G Ex h IIC T4…T2 Gb / II 2D Ex h IIIC T135 °C…T300 °C Db), mechanical equipment rules apply to prevent electrostatic ignition:

Temperature Class	Maximum Permissible Surface Temperature	Permissible Ambient Temperature Range	Maximum Process Medium Temperature
T2	+300 °C	-40 °C to +130 °C	+285 °C
T3	+200 °C	-40 °C to +130 °C	+185 °C
T4	+135 °C	-40 °C to +100 °C	+125 °C

Grounding and Electrostatic Discharge

The valve body must have an equipotential bonding conductor connected to the plant piping system. All isolated conductive parts and the actuator must be grounded using the external grounding strap clamp and terminal lug. Clean the exterior housing using damp or antistatic cloths only.