What do you expect
Beating my head against the wall
What do you expect
You want to take it all

("What Do You Expect?," by J. J. Cale,  1981)

THE EXPECTED, TYPICAL PUMP INSTALLATION SET UP

PTOA Readers and Students who are reading the PTOA Segments in the intended sequential order just learned that ...

No matter which kind of pump is chosen for a process industry service ...

each pump will have:

• A casing that is fabricated to create a Pump Suction and a Pump Discharge.
• A Suction Pressure PI and a Discharge Pressure PI.
• A Pump Suction Pipe aka Pump Suction Line.
• A Pump Discharge Pipe aka Pump Discharge Line.
• A Tank or Reservoir.

In this PTOA Segment #164, PTOA Readers and Students will learn about the hardware components that will be installed on the Suction and Discharge Pipes of all pumps ...

No matter which type of pump is chosen for whatever process industry service.

The Typical Pump Installation Set Up is evident in the nearby photo.

The Suction Valve, Discharge Valve, Strainer, and Check Valve are labelled.

All PTOA Readers and Students who stick with the PTOA will soon be able to identify the hardware components found in the Typical Pump Installation Set Up without any labels ...

and that will certainly impress any potential Process Industry employer!

 

REAL & SYMBOLIZED PIPE HARDWARE COMPONENTS
INSTALLED ON PUMP SUCTION AND DISCHARGE LINES

ISA Valve Symbols

The future PTOA PV Flowrate Focus Study Area will focus upon piping hardware and the various methods used to connect pipe segments together ... so don't sweat the details now.

At this juncture PTOA Readers and Students just need to realize that pipe hardware components include Valves and Filters.

Spoiler Alert!

PTOA Readers and Students will learn that ... although there are many types of Valves ...  there are only 4 reasons to add a Valve into the process flow piping.

The above graphic shows the ISA symbols for popular process industry Valves.

For example, one of the most common process industry Valves is the Gate Valve.

Gate Valves are used to start or stop the process flow.

That means that Gate Valves will either be totally open or totally closed.

The ISA symbol for a Gate Valve looks like a bow tie.

A real world manually operated Gate Valve is in the nearby photo.

This model has a blue hand wheel.

 

 

 

 

 

 

 

 

 

The Typical Pump Installation Set Up

The Typical Pump Installation Set-up is shown in the below diagram ...

Don't fret, the symbols will be explained, right after a little "decoding of the schematic."

Note that the Centrifugal Pump in the diagram does not have the "backwards C." The symbol is also missing the Discharge Line spout ... because it was drawn with a cheap CAD program.

In this case Your Mentor can infer the diagram is showing a Centrifugal Pump that adds the PV Pressure to liquids and not a Centrifugal Compressor that adds the PV Pressure to gases.

The drains are a dead giveaway. Liquids drain. Gases don't drain.

Now direct your attention to the bottom left of the diagram.

Although there are no arrows indicating flow, believe Your Mentor  that the process stream liquid is flowing from its Tank/Reservoir and enters the diagram on the bottom left.

Find the below hardware components on the Typical Pump Installation Set Up diagram.

• A Suction Valve on the pump's Suction Line is a Gate Valve ... it is  before the UC/Drain and looks like a bow tie.
• A Discharge Valve on the pump's Discharge Line is also a Gate Valve... it also looks like a bow tie and is located just after the ....
• Check Valve  ... which looks like "Z" with an arrow pointing the desired direction of flow.

The purpose of a Check Valve is to prevent flow from going in the non-desirable, reverse direction. The arrow on the check valve body indicates the desired flow direction.

 

PTOA Readers and Students will soon learn why ...

Each Valve is installed for a specific purpose ... no Valve is just randomly stuck in there for grins.

Don't stress about the piping hardware shown in the upper region of the schematic; PTOA Readers and Students will learn all about it in the future PTOA PV Flowrate Focus Study Area.

In the nearby real world photo, the Suction and Discharge Gate Valves are easily identified by their black hand wheels.

The Check Valve is on the Discharge Line, bolted in-between two segments of piping that have flanged ends... (just look for a  drain spout pointing down).

 

 

 

 

 

 

Hardware Components That are Needed for Pump Malfunction

The Typical Pump Installation Set Up must take into account this question:

What happens if the Pump malfunctions?

PTOA Readers and Students who are reading the PTOA Segments in the intended sequential order already know that critical-service pumps are installed in pairs ... a Primary Pump and a Back-Up Pump.

Logically, the Back Up Pump is placed in service while the malfunctioning pump is repaired.

So also logically, some piping component hardware must exist to "block in and isolate" the malfunctioning pump from the process fluid ...

because the process fluid must still continue flowing so that raw materials can continuously be upgraded to more valuable products.

 

The General Steps To Prepare a Pump for Maintenance

The hardware piping components that are purposely installed to make it possible to "swap a pump out for maintenance" are explained below ...

While the actions that an Outside Process Operator follows to bring the malfunctioning pump "off-line" are simultaneously explained.

In general the procedure will include the following actions:

• 

  This pump starts automatically.

  The Outside Process Operator will either initiate the written procedures to start the Back Up Pump or it will be started up automatically via automatic instrumentation.

• In either case the Outside Process Operator will confirm that the Back Up Pump is working after having been offline prior to proceeding to the next step because a limping pump is better than no pump at all.
• The Outside Process Operator will depress the "Stop Button" on the malfunctioning pump's driver so it will stop its spinning or reciprocating action.
• The Outside Process Operator will Block In the Suction Valve and Discharge Valve of the malfunctioning Pump.

 

In Process Operator jargon, the phrase "Block in" means "to close tightly and completely."

• The Outside Process Operator will open the drains and vents shown around the pump so that the process liquid, lube oil, and hot vapors from the malfunctioning pump are drained via environmentally conscious procedures (DO NOT DUMP OIL on the ground!).

The Typical Pump Installation Set Up must also take into account this question:

What would happen if the Suction Valve or Discharge Valve were found to be leaking ... and maintenance still must be completed on the pump?

Opening up the two drains to sewer would encourage the leaking process fluid to "take the easy way out" and flow to the drain or sewer ... but this plan-of-attack would not be a safe procedure nor would it comply with environmental permitting. 

The designed-in solution is:

• The Process Operator will "swing the spectacle blinds" on the Pump Suction Line and Pump Discharge Line "to the closed position."

 

The spectacle blinds  on the diagram are those Figure 8 shaped things that look like spectacles (eyeglasses).

Take the time to locate the  "spec blind" on the diagram. It is between the Suction Gate Valve and the (labelled) Drain.

The dark circle represents a metal surface that, when swung into place, creates a physical barrier in the pipe that prevents flow from getting through. (Don't Stress! Pipe Fittings will be featured in the PTOA PV Flowrate Focus Study Area).

Although not shown on the Typical Pumping Installation Setup schematic, there will always be a Filter or Strainer of some type on the Suction side of the Pump.

The Filter/Strainer removes debris that would scratch the internal working surfaces of any Pump.

 

 

Centrifugal Pumps Require Suction Line Contraction
Followed by Discharge Line Expansion

See the two thimble-looking things, one piped in prior to the Pump Suction and the other piped in after the Pump Discharge?

These symbols indicate the pipe diameter is intentionally decreased just prior to the Pump Suction and increased after the Pump Discharge.

The change in piping diameters is a permanent, planned feature of the piping scheme that is needed for centrifugal action to work properly and is not related to the maintenance interval.

So the complete Typical Pump Installation Setup For A Centrifugal Pump is shown in the below schematic:

PTOA Readers and Students will soon expertly understand centrifugal action ... do don't fret about that now!

TAKE HOME MESSAGES: There is a Typical Pump Installation Set Up that is common to all pumps, no matter what their style of process service is.

The component hardware in the Typical Pump Installation Set Up includes:

• Suction Valve and Discharge Valves, which are typically gate valves that can be totally open or totally closed.
• Check Valve on the Discharge Pipe/Line to prevent backflow into the Pump Discharge.
• Filter or Strainer prior to Pump Suction.
• Pump Casing and Piping Drains.

The typical component pump piping hardware may also include: 

• Suction and Discharge Spec Blinds.
• Pipe Diameter Reducer prior to Centrifugal Pump Suction.
• Pipe Diameter Expander at Centrifugal Pump Discharge. 

This PTOA Segment included the general procedure that all Outside Process Operators follow to "swap out a pump for maintenance".

The Outside Process Operator must always verify the status of the Back Up Pump prior to shutting down the Primary Pump (a limping Primary Pump is better than no pumping action at all). 

©2017 PTOA Segment 0164
PTOA Process Variable Pressure Focus Study Area
PTOA PV Pressure Rotating Equipment Focus Study

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