Pipeline ancillaries

HVB3aslltvoaplveaslve

ISO 9001

7.4.53

For liquids

Where:

Sub-critical flow

When:

DP < DPm

Volumetric flowrate

pr

∆P

Cv =

��

865 ∆Ppr

Critical flow

When:

DP > DPm

Volumetric flowrate

Cv =

1.16��

pr

F

L

∆Pm

Mass flowrate

DPm =

Cv =

F

L

=

pr =

P

1

=

P

2

=

P

V

=

Pc =

V =

m=

Maximum DP for sizing,

WhenP

2

>PvuseDPm=F

L

2(P

1

-Pv)



Pv 

WhenP

2

≤ PvuseDPm=P

1

- 0.96-0.28

P

 Pv

Flow coeffecient of the valve

Pressure recovery factor

Density at inlet temperature (water = 1.0 at STP)

Upstream pressure (bar a)

Downstream presure (bar a)

Vapour pressure of the liquid at inlet temperature (bar a)

Thermodynamic critical pressure (bar a)

Flowrate in m3/h

Flowrate in in kg/h



c





Cv = 1.16��

Mass flowrate

Cv =

��

865 F

L

pr∆Pm

TI-P133-46

ST Issue 1

Cert. No. LRQ 110478

Description

M15 ISO

Ball Valve for Control of Fluids

Sizing Sheet

The M15 ISO ball valve is ideal for control applications. Both ball

and seat are manufactured in chrome plated metal which ensures a

long life, even with applications that constantly modulate the flow of

the fluid. The valve is actuated by a double or single acting pneumatic

actuator. The actuator is regulated by an electropneumatic positioner

that receives a 4 - 20 mA signal from the process.

Advantages:

-

Inherentequalpercentageflowcharacteristicwith

high rangeability (32:1).

-

Suitableforfluidsthatcontainsolidsinsuspension.

-

Capacityismuchhigherthanasamesizeglobevalve.

-

Lessmaintenancethanspindleregulatingvalves.

-

Small,compactandeasilymaintained.

Sizing

1. DeterminetherequiredCvfortheballvalveusingtheappropriate

equation detailed below. With the first approximation for this

calculation it is suggested to use a factor F

L

= 0.68, that

corresponds to an opening of the valve of 72°.

2. Calculate the diameter of the pipe for maximum flow within the

limits of velocity and pressure drop for the fluid.

3. With the Cv and pipe diameter, use the table overleaf starting

with the column that corresponds to the rotation of 72°, that gives

F

L

= 0.68.

4. In this column, choose the combination of ball valve diameter

and pipe diameter that gives a Cv result the same or superior to

the one calculated in step 1.

5. It is recommended not to use a ball valve with a diameter less

than half the pipe diameter, because of excessive tension that

can produce vibrations.

Simplified equations for sizing (Kv values = Cv x 0.86)

Local regulations may restrict the use of this product to below the conditions quoted.

In the interests of development and improvement of the product, we reserve the right to change the specification.

© Copyright 2002