javascript code 39 barcode generator Pressure reduction in Software

Printer QR in Software Pressure reduction

622 Pressure reduction
Quick Response Code Drawer In None
Using Barcode generation for Software Control to generate, create QR image in Software applications.
Scanning Quick Response Code In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
When steam is distributed from a central plant, it may be desirable to use higher pressures for distribution, resulting in smaller piping Then it is usually necessary to use pressure-reducing valves (PRVs) to provide a suitable point-of-use pressure A typical pressure-reducing station is shown in Fig 61 To provide better control, it is common practice to use two PRVs in parallel, one sized for one-third and the other sized for two-thirds of the load, respectively, and sequenced so that the smaller valve opens rst This allows the larger valve to work against smaller pressure differentials, which helps to avoid wire drawing of the valve seat at low loads A manual bypass with a globe valve is provided for emergency use The PRV should have an internal or external pilot, for accurate control of downstream pressure regardless of upstream changes The maximum pressure drop through any steam PRV at the design ow rate is about one-half of the entering pressure; more exactly, the ratio of downstream to upstream pressure cannot be less than 053 This is due to the physical laws governing ow of compressible uids
Generate Quick Response Code In C#
Using Barcode drawer for .NET framework Control to generate, create Denso QR Bar Code image in VS .NET applications.
Generate QR Code 2d Barcode In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create QR image in ASP.NET applications.
Downloaded from Digital Engineering Library @ McGraw-Hill (wwwdigitalengineeringlibrarycom) Copyright 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website
Quick Response Code Drawer In .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create QR-Code image in .NET applications.
Quick Response Code Generator In Visual Basic .NET
Using Barcode printer for Visual Studio .NET Control to generate, create QR Code JIS X 0510 image in .NET framework applications.
Design Procedures: Part 4 148 Six
Making Bar Code In None
Using Barcode printer for Software Control to generate, create barcode image in Software applications.
Make ECC200 In None
Using Barcode encoder for Software Control to generate, create Data Matrix ECC200 image in Software applications.
Figure 61 Pressure-reducing station
Draw UPC-A Supplement 2 In None
Using Barcode creator for Software Control to generate, create UPC-A Supplement 5 image in Software applications.
UCC-128 Encoder In None
Using Barcode creator for Software Control to generate, create GS1-128 image in Software applications.
through ori ces If greater pressure reductions are required, it is necessary to use two or more stages, as shown in Fig 62, or to use an oversized PRV, preferably sized by the manufacturer
EAN-13 Encoder In None
Using Barcode printer for Software Control to generate, create UPC - 13 image in Software applications.
Draw Code 39 In None
Using Barcode creator for Software Control to generate, create Code 39 Extended image in Software applications.
623 Steam condensate
Paint UPC-E Supplement 5 In None
Using Barcode printer for Software Control to generate, create UPC-E image in Software applications.
Barcode Decoder In .NET Framework
Using Barcode Control SDK for ASP.NET Control to generate, create, read, scan barcode image in ASP.NET applications.
Condensate is usually returned to the boiler for reuse In small systems, this can sometimes be done by gravity In most systems, pumping is required The condensate ows by gravity to a collecting tank from which it is pumped directly to the boiler or to a boiler feed system, as described in Chap 7 Condensate is basically distilled water It often includes dissolved carbon dioxide, making a weak but corrosive carbonic acid The cor-
Barcode Maker In Java
Using Barcode printer for BIRT reports Control to generate, create barcode image in Eclipse BIRT applications.
Barcode Printer In Java
Using Barcode maker for Java Control to generate, create barcode image in Java applications.
Figure 62 Two-stage pressure-reducing station
Code 128A Maker In None
Using Barcode generation for Office Word Control to generate, create Code 128B image in Microsoft Word applications.
Making UCC - 12 In Java
Using Barcode creator for Java Control to generate, create GTIN - 12 image in Java applications.
Downloaded from Digital Engineering Library @ McGraw-Hill (wwwdigitalengineeringlibrarycom) Copyright 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website
USS Code 39 Printer In Java
Using Barcode printer for Java Control to generate, create ANSI/AIM Code 39 image in Java applications.
Encode Barcode In Java
Using Barcode creator for BIRT Control to generate, create barcode image in BIRT applications.
Design Procedures: Part 4 Design Procedures: Part 4 149
rosive character of condensate must be addressed in condensate piping material selection 63 Water
Water is used extensively in modern cooling and heating practice because it is an effective heat transport medium and because it is considered simple to deal with Because the water system can be essentially closed, there are fewer corrosion and water treatment problems than with steam Except in high-rise buildings, system static pressures are low and temperature changes are not severe, allowing the use of low-cost materials and simple piping support systems An exception is high-temperature hot water, discussed later in this chapter
631 Water properties
Refer to Tables 61 and 62 for water properties over a wide range of temperatures and corresponding pressures The enthalpy of water over this range changes at a rate of about 1 Btu/(lb F) For design purposes, this value can be used without signi cant error The density of water varies from 623 lb/ft3 at 70 F to 601 lb/ft3 at 200 F For HVAC design purposes, the value of 623 lb/ft3 is commonly used; it is suf ciently accurate over a range from 32 to 100 F but should be compensated for at higher temperatures Based on 75 gal/ft3, 1 gal weighs about 83 lb Then 1 Btu/(lb F) 83 lb/gal 60 min/h 500 Btu/[h (gal/min) F] (61)
which is a constant commonly used in calculating water ow quantities To determine the water quantity required to serve a given load, divide the load, in Btu per hour, by 500 and by the desired water temperature drop or rise in degrees Fahrenheit Typical numbers are 8, 10, and 20 F for cooling (resulting in a divisor of 4000, 5000, and 10,000, respectively) and 20 to 40 F for heating (a divisor of 10,000 to 20,000) Another measure of water quantity is gallons per minute per tonhour of refrigeration Because 1 ton h equals 12,000 Btu/h, a 10 F rise in the chilled water temperature works out to 24 gal/(min ton) An 8 F rise requires 3 gal/(min ton), and a 20 F rise is 12 gal/ (min ton) On the condensing water side, it is assumed that heat rejection in a vapor compression machine is approximately 15,000 Btu/(ton h) and a 10 F rise requires 3 gal/(min ton h) The
Downloaded from Digital Engineering Library @ McGraw-Hill (wwwdigitalengineeringlibrarycom) Copyright 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website
Copyright © OnBarcode.com . All rights reserved.