Instruction Manual
D100425X012
YD and YS Valves
July 2017
3
Installation
WARNING
Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal
injury.
Personal injury or equipment damage caused by sudden release of pressure might result if the valve assembly is installed
where service conditions could exceed the limits given in table 1 or on the appropriate nameplates. To avoid such injury or
damage, provide a relief valve for overpressure protection as required by government or accepted industry codes and good
engineering practices.
Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
If installing into an existing application, also refer to the WARNING at the beginning of the Maintenance section in this
instruction manual.
CAUTION
When ordered, the valve configuration and construction materials were selected to meet particular pressure, temperature,
pressure drop, and controlled fluid conditions. Responsibility for the safety of process media and compatibility of valve
materials with process media rests solely with the purchaser and end‐user. Since some body/trim material combinations
are limited in their pressure drop and temperature ranges, do not apply any other conditions to the valve without first
contacting your
Emerson sales office
or Local Business Partner.
Before installing the valve, inspect the valve and pipelines for any damage and any foreign material which may cause
product damage.
1. Before installing the valve, inspect it for any shipping damage and for any foreign material in the valve body cavity.
2. Clean out all pipelines to remove pipe scale, chips, welding slag, and other foreign materials.
3. Use accepted piping and welding practices when installing the valve. For flanged valves, use suitable gaskets
between the valve and the pipeline flanges.
4. Do not install the valve in a system where the working pressures exceed those specified in the ASME
pressure/temperature ratings or those specified by Emerson Automation Solutions.
5. If continuous operation is required during maintenance and inspection, install a conventional three‐valve bypass
around the valve so that the valve can be isolated.
6. Orient the valve so that flow will be in the direction indicated by the flow arrows.
Note
The common port for the YD is the bottom port as shown on the flow direction plates (key 17) in figure 10. The common port for
the YS is the left‐hand port as shown on the flow direction plates in figure 9.
CAUTION
Depending on valve body materials used, post weld heat treating may be required. If so, damage to internal elastomeric
and plastic parts, as well as internal metal parts is possible. Threaded connections may also loosen. In general, if post weld
