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By: Pratham Gupta

Jayant Kashyap

Vivek Kumar

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Do you have any idea?

How many valves are there in the McMaster

Boiler House??

450!

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Valve Selection

VALVE BODY + ACTUATOR

CONTROL VALVE!

=

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Gate

Globe

Diaphragm

ButterflyValve

Types of Valves

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Diaphragm

Piston

Electric

Hydraulic

Types of Actuators

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Selection of Valves

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Valve SizingThe 6 Steps to Sizing a Valve are:

1. Define the System

2. Define a maximum allowable pressure drop forthe valve

3. Calculate the valve characteristic

4. Preliminary valve selection

5. Check the Cv and stroke percentage at theminimum flow

6. Check the gain across applicable flow rates

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Valve SizingStep 1. Define the System

Imagine a system pumping water from onetank to another through a piping system:

total pressure drop = 150 psi

The fluid is water at 70 0F

Design flow rate of 150 gpm, operating flow rate of110 gpm, and a minimum flow rate of 25 gpm

The pipe diameter is 3 inches

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Valve SizingStep 2. Define a maximum allowable pressure dropfor the valve

A valve should be designed to use 10-15% of the total pressuredrop or 10 psi, whichever is greater.

What would the pressure drop over the valve be in OUR system??

15 psi!

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For our system,

Valve SizingStep 3. Calculate the valve characteristic

Therefore, the flow charactertistic for this system is 39

Note that this Cv is with the valve at 100% open

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Valve Arrangements

1. Series

2. Parallel

3. Series & Parallel

4. Bypass

5. Double block & Bleed

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Economics

0

200

400

600

800

1000

1200

1400

1600

1800

2000

1 2 3 4 5 6

Size (inches)

Pounds

Butterfly

Segment Ball

Eccentic Rotary Plug

Globe

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