Danfoss VGS Data sheet

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Data sheet

2 - way valve for steam, pressure relieved (PN 25) VGS - external thread

Description

Ordering

Example: Valve for steam, DN 15; kVS 1.6; PN 25; T

- 1× VGS DN 15 valve

Option:

- 1× Weld-on tailpieces

The valve will be delivered together with two adapters: M34 × M45 and M34 × M30

200 °C; ext. thread

max

Code No: 065B0787

Code No: 003H6908

VGS is pressure relieved 2-way normally open (NO) valves for steam, designed to be combined with:

- AVT Temperature actuators

- STM Safety temperature monitors

- STL Safety temperature limiters

- AMV(E) 20 / AMV(E) 30 electrical actuators

- AMV(E) 23 / AMV(E) 33 electrical actuators with spring return function

In combination with AVT temperature actuators and AMV(E) electrical actuators, valves can be used for temperature control with steam or hot water up to 200 °C.

Main data:

• DN 15-25

• kVS 1.0 - 6.3 m3/h

• PN 25

• Temperature:

- Steam/circ. water/glycolic water up to 30 %: 2 … 200 °C

• Connections:

- Ext. thread (weld-on, thread and flange tailpieces)

• Flow and return mounting

Picture

DN k

(mm) (m3/h)

20 4.5 G 1 A 065B0789

25 6.3 G 1¼ A 065B0790

1.0

1.6 065B0787

3.2 065B0788

Cylindrical external

thread acc. to

Connection Code No.

G ¾ A

ISO 228/1

VGS valve

Two adapters are deli vered together with the valve: M34 × M 45 and M34 × M30 (for detai ls see Accessories);

M34 × M45 is factory as sembled on the valve.

065B0786

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Data sheet 2 - way valve for steam, pressure relieved (PN 25)

Ordering (continuous)

Accessories

Picture Type designation DN Connection Code No.

Weld-on tailpieces

20 003H6909

25 00 3H6910

External thread tailpieces

Conical ex t. thread acc. to

20 R ¾ 003H6903

25 R 1 003H6904

EN 1022 6-1

R ½ 003H6902

Flange tailpieces

20 003H 6916

Flanges PN 25, acc. to EN 1092-2

25 0 03H6 917

Adapter

Adapter for VGS combi nations with electrical a ctuators type AMV(E) 20, 23, 3 0, 33.

Adapter for VGS combina tions with temperature act uators AVT, temperature monito rs STM and temperature limi ters STL.

M34 × 1.5 mm / M30 × 1.5 mm 003H18 35

M34 × 1.5 mm / M45 × 1.5 mm 003H6927

Service kits

Picture Type designation for valves DN k

15 3.2

Valve body extension with stuf fing box

25 6.3

003H6908

003H6915

Code No.

003H687720 4.5

Technical data

Nominal diameter DN 15 20 25

value m3/h 1.0 1.6 3. 2 4.5 6.3

Stroke mm 3 5

Control ratio >1: 50

Control characteristic linear

Cavitation factor z ≥ 0.6 ≥ 0.55

Leakage acc. to standard IEC 534 % of k

Nominal pressure PN 25

Max. differential pressure bar 10

Medium Steam / Circulation water / Glycolic water up to 30%

Medium pH Min. 7, max. 10

Medium temperature

Connections

valve External thread

tailpieces Weld-on, external thread and flange

C 2 … 200

Materials

Valve body Red bronze CuSn5ZnPb (Rg5)

Valve seat Stainless steel, mat. No. 1.4571

Valve cone Stainless steel, mat. No. 1.4122

Pressure relive system Bellows

≤ 0.05

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Data sheet 2 - way valve for steam, pressure relieved (PN 25)

Application principles

Pressure temperature diagram

CuSn5ZnPb (Rg5) PN 25

Maximum allowed operating pressure as a function of medium temperature (according to EN 1092-3).

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Data sheet 2 - way valve for steam, pressure relieved (PN 25)

Installation position

Valves can be installed in any position.

Temperature controller and safety temperature monitor

STM / VGS + AVT + adapter M34/M45 (003H6927)

Up to medium temperature of 160 °C temperature controller AVT/VGS and safety temperature monitor STM/VGS can be installed in any position.

Electrical actuator

Note!

Installation positions for electrical actuators AMV(E) have to be observed as well. Please see relevant Data sheet

For higher temperatures temperature controller AVT/VGS and safety temperature monitor STM/VGS have to be installed horizontal and in horizontal pipes with the actuator oriented downwards.

Safety temperature limiter

STL + VGS + adapter M34/M45 (003H6927)

Up to medium temperature of 100 °C safety temperature limiter VGS + STLS can be installed in any position.

For higher temperatures safety temperature limiter VGS + STL have to be installed in horizontal pipes only, with a pressure actuator oriented downwards.

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Data sheet 2 - way valve for steam, pressure relieved (PN 25)

Sizing

Steam valve sizing is based on 40 % drop of the steam pressure across the valve when fully open. At this condition the steam is travelling at or close to its critical velocity (approx. 300 m/s) and throttling would occur over the full valve stroke.

If the steam is travelling slower than this, then the first part of the valve stroke would merely increase the velocity of the steam without reducing the volumetric flow.

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Data sheet 2 - way valve for steam, pressure relieved (PN 25)

Sizing (continuous) 1. For saturated steam

Given data:

Flow rate: 70 kg/h Absolute inlet pressure: 5 bar (500 kPa)

Remark:

For this example follow dashed line

The absolute inlet pressure is 500 kPa. Critical pressure drop (40% of 500 kPa) is 200 kPa. Locate the diagonal line corresponding to the pressure drop of 200 kPa (line A-A).

Read the absolute inlet pressure on the lower left hand scale (point B), and draw a horizontal line across until it meets the pressure drop diagonal A-A at point C.

From this point C extend a vertical line upwards until it meets the horizontal line representing the steam flow of 70 kg/h from point D. The intersection of this is point E.

The nearest diagonal kVS line above this is line F-F with a kVS of 1.6. If the ideal valve size is not available the next largest size should be selected to ensure design flow.

The pressure drop through valve at the flow rate is found by the intersection of the 70 kg/h line with F-F (point E’) and dropping a vertical line downwards; this actually hits the horizontal line for 500 kPa absolute inlet pressure (point E’’) at a pressure drop diagonal of 90 kPa. This is only 18 % of the pressure drop accross the valve and the control quality will not be good until the valve has partially closed. As with all steam valves this compromise is necessary since the next smaller valve would not pass the required flow (maximum flow would be about 60 kg/h; point P).

The maximum flow for the same inlet pressure is found by extending the vertical line (C-E) through point E until it crosses the kVS 1.6 line F-F (point G) and reading off the flow (90 kg/h).

2. For superheated steam

Given data:

Flow rate: 170 kg/h Absolute inlet pressure: 5 bar (500 kPa) Steam temperature: 190 °C

Remark:

For this examp le follow dotted line The procedu re for superheated steam is mu ch the same as for saturated steam , but uses a different fl ow scale which slightly elevates the rea dings according to the degree of su perheat.

As before, the diagonal critical pressure drop line A-A is located at 40 % of 500 kPa (200 kPa). The horizontal inlet pressure line through point B is now extended to the left to read off the corresponding saturated steam temperature at point H (150 °C). The difference between the saturated steam temperature and the superheated steam temperature is 190 °C − 150 °C = 40 °C (see point J).

The superheated steam flow 170 kg/h is found on the upper right hand scale (point K). From here the diagonal line is followed down until it meets a vertical line from the steam temperature elevation (40 °C, point J) at point L.

As before, the horizontal line through point B is drawn to cut line A-A at point C. The point where the vertical line from point C meets the horizontal line from point L is the operating point (point M). This horizontal line, L-M, is the corrected flow line. The nearest diagonal line above this is line N-N with a kVS 3.2. A vertical line dropped from the intersection of L-M line with line N-N (point M’) intersects the 500 kPa absolute inlet pressure line (point M’’) at a pressure drop diagonal of about 150 kPa. This is about 30% of the pressure drop accross the valve which will give reasonable control quality (compared to recommended ratio of 40 %).

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Data sheet 2 - way valve for steam, pressure relieved (PN 25)

Design

1. Valve body

2. Valve insert

3. Pressure relieved valve cone

4. Valve stem

5. Valve body extension

6. Stuffing box

Dimensions

DN 15 20 25

VGS

H 156 .5 155 158 .5

65 70 75

Weight kg 0.7 0.8 0.9

M34

M30

Adapter

M34 × 1.5 mm / M30 × 1.5 mm

DN R

SW d L

M34 × 1.5 mm / M45 × 1.5 mm

L2L

k d

M34

M45

Adapter

45°

15 ⁄ 32 (G ⁄A) 21 13 0 120 139 65 14 4

20 ⁄ 41 (G 1A ) 26 150 131 154 75 14 4

25 1 50 (G 1⁄A) 33 160 145 159 85 14 4

Conical ex t. thread acc. to EN 10226-1

Flanges PN 25, acc. to EN 1092-2

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Danf already on order pro All trademarks in this material are property of the respec

Data sheet 2 - way valve for steam, pressure relieved (PN 25)

oss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products

vided that such alterations can be made without subsequential changes being necessary eady agreed.

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Danfoss VGS Data sheet

Specifications and Main Features

Frequently Asked Questions

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