Product Handbook 2026 - Volume 1

Flowmetering Gilflo and ILVA flowmeters 3

Step 2.

Using the value of Q E as determined in Step 1, select the correct size of the ILVA flowmeter using the Table below. In practice, it will often be the line size that determines the choice of the flowmeter.

Q E litres / min

Maximum DP

Flowmeter type

q

Maximum

Minimum

Wg

m bar

SG m q SG m

Q = E Q = E

Q = Q SG E L Q = Q SG E L

DN50 DN80 DN100 DN150 DN200

149

1

200

498

585

6

200

498

1000 1000 D F

D

Q = q E Q = q E

1000 F D 1000 F

Q = Q E Q = Q E

M

F

1 200

12

200

498

M

D

F

F

2 900

29

200

498

q

M

Q = E Q = E

57 1 000 P F T S x x D S P S T F P S T F D S 1 000 P F T S x x

q

Q E = Q S Q E = Q S

5 700

200

498

D P T x x 1000 P T S F D P T x x 1000 P T S M S F

S

S

F

Example: Determine which ILVA pipeline unit is required to measure the flow of compressed air when: 1: Estimated maximum rate of flow = 500 s m³/h at 7 bar g and 20 °C Note : Standard conditions = 1.013 bar a, 0 °C giving a standard density of 1.29 kg / m³ S F

3.2 9

D S

P S

D P P x 1000 P T 1.29 1.013 293 x 1000 P T 1.29 1.013 293 x x x 1000 8.013 273 S F F S S T F T S D P P F F F x x x 1000 8.013 273 S S S T S

Q

E = Q S E = Q S

x x x x

Q = Q E 1 000 P F Q = Q 1 000 P F S P S E S D S

2: Calculate Q E from:

Q

Q E = 110 litres /min Q E = 110 litres /min Q E = 110 litres/min Q =(500 x 16.667) x E Q =(500 x 16.667) x E

So a DN50 ILVA is recommended. Note: 1 m³/h = 16.667 litres /min

How to order example 1 off Spirax Sarco DN50 ILVA flowmeter suitable for fitting between EN 1092 PN40 connections.

TI-P337-05 EMM Issue 18

Page 5 of 8

ILVA Flowmeter

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