design guide for piping design.pdf

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PRACTICE Page 122 of 129

Design Guide for Piping Arrangement(General) JPEP-0-1360-G-4211 REV.1

Examples of 1in. and 3in. mass flowmeters are shown below.

Example of 3in. mass flowmeter Example of 1in. mass flowmeter

(b) Mass flowmeters shall be installed at least 1m distant from large transformers, motors, etc. which are apt

to cause interference due to electromagnetic induction.

(c) A firm pipe support shall be installed near the location where a mass flowmeters is connected to the

piping. However, the flanges for connection to the piping shall not be supported.

(d) The position of a mass flowmeter installed on horizontal and vertical piping shall be as shown in the

table below.

Fluid Horizontal Line Vertical Line

Liquid

Liquid with Gas ---

Slurry ---





8.6 Control Valve

The function of control valve is a very important part in the automatic operation control system of the units, and the

arrangement of same and its surrounding pipelines is also of great importance in respect of carrying out operation and

maintenance. The purposes of using the control valves are as follows:

(1) Control the process conditions (flowrate, liquid level, pressure, temperature, etc.) by adjusting the flow of the

fluid.

(2) Shut off, release or change over the flow of the fluid.

(3) Mix two fluids, or distribute one fluid to two directions.

8.6.1 Control Valve Assembly

While being laid separately in some cases according to the process purposes, in most cases the control valve

shall be installed together with a block valve, bypass valve, drain removal facilities, etc. to form a control valveassembly. The most typical assembly is shown below.

Control Valve

Downstream side Drain for Control valve to beattached for cases as follows:(a)According to the type of the control valve

(air fail close, single port inner valve).(b)According to the requirement by the client.

Block Valve Block Valve

Upstream side Drainfor Control valve

The control valve to be closedto make “Bypass Operation”shutting-off the functioning ofthe control valve to carry out

Bypass ValveWhen performing “Bypass Opera-tion” , “Manual Control” is done

by this valve in place of the Control





8.6.2 Configuration of Control Valve Assembly Piping

(1) The piping configuration of the control valve assembly is variable depending on the piping route, location in

the arrangement, type of the con-trol valve, etc., however, the most fundamental configuration is shown

below.

When dead space during bypass operation is minimized, the block valve shall be located at a minimized

distance from thebypass valve. When the volume of drain is minimized on the occasion of control valve

detachment,the block valve shall be locaed at a minimum distance from the lower elbow. Which should be

adopted shall depend onthe client’s requirement. According to past experience., the block valve is often

located at a minimum distance from the lower elbow as shown in the figure.

A “Min. 200” shall be secured as a maintenance SPACE for the control valve. Where the bypass valve is

INSULATED, a “Min. 200” shall be kept to the surface of the Insulation.

“MIN. 100” shall be secured as the maintenance space for the control valve. Where the block valve is

Insulated, a “MIN. 100” shall be kept to the surface of the Insulation.

To be as short as possible.

Normally unified by 500 to 600, however, where the lower end of the control end is of the flange-type, the

required dimension for maintenance shall be consulted per the personnel in charge of instrumentation

engineering.

All control valves except for the angle-type shall be installed in the horizontal pipelines.

1

2

3

4

5

6

Pay attention to the size of this reducer because the bolt attaching the control valve might interfere withthe reducer depending on its size.

The above interference might be happening here.

⑨

①

②

③① ①

③ ⑥ ⑤

⑦

⑧

⑧

①

④





Where the size of the larger end of reducers is 6in. or larger, drains may be attached directly.

When the block valve and bypass valve are downsized, reducers shall be installed at minimum distance from

the adjacent valve. This downsizing is aimed at matching with the valve size. When bypass line are

downsized, reducer or reducing tee shall be located according to piping branch table of job piping materialspecification.

Bypass valve shall be located to be minimum dimension from tee of upstream so that dead space of bypass line

(when line is shut off by block valve and bypass valve) is minimized.

(2) Major Configuration of Other Piping

(a) The piping configuration where the Control Valve Assembly is installed in “Downcomer Piping Route” (also

applicable to the reverse flow ) .

7

8

9





(b) Piping Configuration Installed on Platform (where the control valve assembly is located on plaform and piping

come from under the platform.)

(c) Piping Configuration in which the Control Valve Assembly is Set to the Piping on Ground or on a Lower

Elevation of Rack.

If there is no problem regarding space, apply this configuration in

respect of stability in the case of laying the assembly.





(d) Piping configuration in which Valve in Branch Piping is to be Installed on a Lower Elevation for operation.

(e) Piping Configuration in which the Bypass Valve Locates too High to Operate

Notice that the laying space is ratherlong as compared with the one in theright.

Piping arrangement shown in the left shall beapplied if these valves locate too high to operate.

This dimension shall be determined with sufficientreview for existence of interference between the handle

of bypass valve, the body ofcontrol valve and accessories.





(f) Piping Configuration including the Angle Type Control Valve

8.6.3 Installation Location of Control Valve Assembly

The installation location of the control valve assembly shall be determined with sufficient review on the

following matters:

(1) The control valve assembly shall be located at where the process requirements are satisfied.

(2) The control valve assembly shall locate on the ground or on a platform so as to facilitate operation,

maintenance and monitoring.

(3) It is desirable to secure spaces for operation and maintenance, 600 mm min. in front and 300 mm min. behind the control valve assembly.

( Example )

Installation location shall be sufficiently reviewed when there is an indication of “Free drain”.

Spaces for operation andmaintenance

Min.100

600 mm Min.

300 mm Min.





(4) If possible, control valve assemblies are to be installed in groups on considering of appearance, convenience of

operation and maintenance. The location of grouping shall be as follows:

(a) Out-/Inside Center Line of Row of Columns in Longitudinal Direction of Piperack

(b) Grouped Installation on Rack

(b) Grouped Installation on platform

OperatingFront

Operating Front Access-Way Operating

Front

Dimension from the column centerline shall be unified.

(Normally 500 or 1000 mm)

Where a number of control valve assemblies are installed,a minimum of 1 (one) accessway shall be provided between2 two beams.

Operating Front

design guide for piping design.pdf

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