What are Mandatory Spares for Pressure Vessels:- 3

[Venkatachalam Ponnusamy]

Hi..

Refer to the subject we have requirement for supply of Stand alone Pressure vessels to our customer for refinery applications.
Scope includes the following as well:-
1. Mandatory spares,
2. Erection & Commissioning Spares,
3. Two Year Operational Spares.
Understand that for Bare Vessels only Gasket, Bolt & Nuts are the only spares for blinds & Companion Flanges are wherever applicable.
Erection & Commissioning spares, Two Year Operational Spares are understandable which is required during start-up, erection & commissioning & during the time of two years operation of plants.
What is mandatory spares for Pressure Vessels and when it is required.. request you to share your thoughts / experience.

 

[LittleInch]

I suspect this is just a generic clause in case some jurisdiction requires some specific spares, but I can't think of anything for Pressure vessels that isn't covered by items 2 and 3.

Of course it depends what is being supplied - just the PV or all the added safety valves, bursting discs etc?
Then there might be a local requirement for some spares not included, but each system will be different.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[staticmh]

Its totally depend on plant to plant and varied based on specification to specification which acceptable to different region of end user.

In Gulf most of the time, below are the requirement that we encourage to utilize:
Spares for Commissioning & Start-up:

1- Bolting – 10% of each size (2 sets min.) including blinded-off nozzles & internal flanges.
2- Gaskets – 2 sets (per joint) including blinded-off nozzles & internal flanges.

Initial Spares (First Two Years of Operation):

1- Bolting – 10% of each size (2 sets min.) including blinded-off nozzles & internal flanges.
2- Gaskets – 2 sets (per joint) including blinded-off nozzles & internal flanges.

 

[r6155]

Also some paint to repair damage during transport or assembly.

Regards

 

[MJCronin]

staticmh, in my opinion, gives good advice ...

With the exception of manway gaskets, his quantities match what I have seen specified in the past.

I have seen five sets of manway gaskets for each manway required by the client's maintenance departments.

Also, there are some odd bits and pieces that can be understood to be "pressure vessel spare parts"

Some examples of these are:

- Spare mechanical seals and seal parts for agitators/mixers

- Spare internal screens/filters for vessels acting as liquid separators

- Spare internal gaskets for certain shell and tube heat exchangers

- Anybody else ????

MJCronin
Sr. Process Engineer

 

[Christine74]

A few decades ago it was not unusual to request spare bolts and gaskets with every new pressure vessel, but more recently it's been acknowledged that almost any gasket can be manufactured and delivered in just a few hours and almost any bolt can be obtained the same day, so the requirement for spare bolts/gaskets is mostly being dropped from client specifications. Most common manway bolts/gaskets are readily available off the shelf.

If a typical oil refinery or large chemical plant kept spare gaskets/bolts for every one of their manways it would fill a huge warehouse, wasting resources that could be better allocated toward keeping an inventory of spare parts for items that have lead times of weeks/months.


-Christine

 

[SnTMan]

If a typical oil refinery or large chemical plant kept spare gaskets/bolts for every one of their manways it would fill a huge warehouse...

Plus they likely could not be properly located and identified when needed

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[weldstan]

It was always bolts and gaskets many years ago - back in the '70s and '80s. Specs often have a life of their own.

 

[DriveMeNuts]

Some flanges or components will never be disassembled during the life of the vessel, except during an unplanned extraordinary event that may require a replacement part.

Some industries such as petrochem where a shutdown costs millions of dollars per day aren't interested in hoping that the component is in stock, and aren't interested in waiting two days for delivery.

They want the component on site, even though it may never be used.

The Mandatories list is specific to the company, equipment, application etc.

 

[Christine74]

If that were true, then certainly API Standard 660 would require a set of spare gaskets be supplied with each new heat exchanger. After all, heat exchangers almost always require custom-made gaskets.

But API 660 doesn't require spare gaskets and hasn't for years. Maintaining an inventory of tens of thousands of heat exchanger gaskets for decades in a refinery warehouse might not be practical.


-Christine

 

The answers can be found in the Purchase Order.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[DriveMeNuts]

Mandatory spares are left to the user's discretion to specify in the PO documentation.

Petrochem refineries use standard flanges and bolts. There is no need for a warehouse of spares for each standard repeat item.

For a custom electric heater and shell, a mandatory spare would be a replacement bundle (including custom gasket).

 

[FacEngrPE]

The term Mandatory spares is a bit loose in definition for a competitively bid pressure vessel. Consider that it might be appropriate to present the pressure vessel as a base bid, and the spares as extra cost line items.

 

[r6155]

See PIP VESV1002 Vessel Fabrication Specification (May2009)
For flanged joints specified to be furnished with service gaskets, a spare
gasket (in addition to any required for initial field assembly in Section
8.3.12) shall be furnished and suitably packaged, marked, and shipped with
the vessel for the following joints: flanged joints having other than ASME
B16.5 or B16.47 flanges with other than commercially available sheet or
laminate gaskets. Unless otherwise specified, one set of unused service
gaskets shall be furnished by the Manufacturer for non-ANSI body flanges
and other non-standard flanges. Service gaskets used for testing shall be left
installed for all blind flanged connections.

Regards

 

[jtseng123]

PIP is just one of hundreds of specs out there. It all boils down how the end user and their maintenance team wants.