# Experiment 10

Topics: Valve, Gate valve, Fluid dynamics Pages: 6 (1962 words) Published: April 21, 2013
Experiment 10 - Flow Characteristics of Valves

NAME: CHER SUNG KANG

GROUP NUMBER: B21

EXPERIMENT NUMBER: 10

DATE OF EXPERIMENT: 28/11/2011

DATE OF REPORT SUBMISSION: 5/11/2011

MARK/20 (for demonstrator use):

Introduction
Aim: 1. Describe operation of various types of valves
2. Measure frictional losses due to flows through different valves 3. Identify sources of errors

Background & theory: In this experiment, the relationship between volumetric flow rate and percentages of valve opening is determined by knowing that volumetric of flow rate of air through the flow meter is proportional to the square root of the differential head across the manometer. Graph of volumetric flow rate (%) vs valve opening (%) can be plotted from the relationship Q α √∆P where in this case becomes Q α √∆h where Q is the volumetric flow rate and √∆h is the square root of the differential height of manometer. By plotting this graph for globe and gate valve, different trend can be observed and frictional losses can be analysed.

Industrial use: This experiment is related to the use of different valves for different purposes. For instance, gate valve is commonly used for shutting the flow of the pipeline while globe valve is generally used as a control valve. The conditions such as pressure of the pipeline system have to be suitable for the valves used. The hazards and safety practice involved in this experiment are very vital in industrial use especially when there are explosive fluids involved.

Experimental Setup:
Manometer
Manometer

Tapered Side
Tapered Side
Orifice Plate
Orifice Plate
Globe Valve
Globe Valve
Gate Valve
Gate Valve
Pump/Blower
Pump/Blower

Legends

Flow of air
Flow of air

Hazards and Safety
Wear lab coat and goggles at all times throughout the experiment. Use stand and use valve stand when connecting the pipe joints. When the valve is fully shut, do not leave blower on for too long in case pressure build up in the system. Dismantle the equipment with bolts slightly lose when breaking a joint between pipe-work. Ensure there is adequate space for work. Keep out all the spanners and bolts which are not in use. Ensure the floor is dry and hands are dry when operating electrical appliances.

Method
Refer to Year 1 Lab Handbook 2011-2012.
Observations
Gate Valve| first set | 2nd set | 3rd set |
valve opening (turn)| h1 (cm)| h2 (cm)| ∆h (cm)| h1 (cm)| h2 (cm)| ∆h (cm)| h1 (cm)| h2 (cm)| ∆h (cm)| 0.0| 32.2| 48.0| 15.8| 32.2| 47.7| 15.5| 32.3| 47.8| 15.5| 0.5| 32.3| 47.8| 15.5| 32.3| 47.8| 15.5| 32.3| 47.8| 15.5| 1.0| 32.2| 47.9| 15.7| 32.3| 47.8| 15.5| 32.3| 47.8| 15.5| 1.5| 32.4| 47.7| 15.3| 32.4| 47.6| 15.2| 32.4| 47.6| 15.2| 2.0| 32.8| 37.5| 4.7| 32.6| 47.4| 14.8| 32.7| 47.4| 14.7| 2.5| 33.1| 47.0| 13.9| 33.0| 47.0| 14.0| 33.0| 47.0| 14.0| 3.0| 33.7| 46.5| 12.8| 33.3| 46.4| 13.1| 33.6| 46.4| 12.8| 3.5| 34.6| 45.5| 10.9| 34.4| 45.5| 11.1| 34.5| 45.5| 11.0| 4.0| 36.0| 44.0| 8.0| 35.8| 44.0| 8.2| 35.9| 44.0| 8.1| 4.5| 38.1| 41.8| 3.7| 37.7| 41.9| 4.2| 38.0| 41.9| 3.9| 5.0| 39.7| 40.1| 0.4| 39.5| 40.0| 0.5| 39.7| 40.1| 0.4| 5.5| 39.9| 39.9| 0.0| 39.7| 39.8| 0.1| 39.8| 39.9| 0.1|

Globe Valve| first set| 2nd set| 3rd set|
valve opening (turn)| h1 (cm)| h2 (cm)| ∆h (cm)| h1 (cm)| h2 (cm)| ∆h (cm)| h1 (cm)| h2 (cm)| ∆h (cm)| 0.0| 35.1| 44.9| 9.8| 35.0| 44.8| 9.8| 35.2| 44.9| 9.7| 0.5| 35.3| 44.9| 9.6| 35.1| 44.8| 9.7| 35.2| 44.9| 9.7| 1.0| 35.2| 44.8| 9.6| 35.2| 44.7| 9.5| 35.3| 44.8| 9.5| 1.5| 35.3| 44.7| 9.4| 35.3| 44.6| 9.3| 35.3| 44.8| 9.5| 2.0| 35.3| 44.7| 9.4| 35.3| 44.6| 9.3| 35.4| 44.7| 9.3| 2.5| 35.3| 44.7| 9.4| 35.3| 44.6| 9.3| 35.4| 44.7| 9.3| 3.0| 35.4| 44.6| 9.2| 35.3| 44.6| 9.3| 35.4| 44.6| 9.2| 3.5| 35.7| 44.6| 8.9|...