Pressure Vessel Specification: From Owner Spec to a Priced Quote

If you have quoted a carbon steel vessel against an owner's pressure vessel specification, you know the price is not built from the ASME code alone. A large part of it comes from pages the code never sees.

Take the bid package that Engineers India Limited (EIL) issued in 2013 for Bharat Petroleum's Kochi Refinery. It runs to 283 pages, and on page 125 one sentence replaces the standard's rule for spot radiography.

Page 143 then says the strictest rule governs. In the example quote below, the choice between those two pages is worth $5,800, and nothing in the package settles it.

This guide is about the quote itself. It shows how a priced quote for a pressure vessel is built from a bid package, line by line: what each line holds, what drives its price, which page sets it, and where the package leaves money open.

It is written for estimators, proposal engineers and applications engineers at ASME vessel shops, and for the managers who sign their quotes.

The worked example is a draft quote for one vessel from the Kochi package, priced with sample rates.

If you are new to reading whole bid packages, start with what five real bid packages taught us, and then come back here for the pricing.

In brief

• A vessel quote is a list of lines, and every line should point to the page that set it. In the example, ten lines cover plate, nozzles, welding, head stress relief, radiography, the hydrotest, inspection, documents, paint and one item on hold.
• The data sheet can hide a cost. The Kochi data sheet says PWHT "NIL", but the heads still need stress relieving, which is a $6,900 line in the example.
• Price every open decision both ways. The spot radiography rule moves the total from $147,820.00 to $153,620.00, so the draft carries one reading and shows the other with its price.
• Write TBD instead of guessing. The level instrument nozzles are on hold, so their line says TBD and becomes a question for the customer.
• Check the bid rule before you write anything into the offer. Under EIL's rules an offer that carries a clarification is liable for rejection, so every question has to reach the customer before the due date.

What a pressure vessel quote contains, line by line

A quote for a pressure vessel is a set of costs, and each cost is there because some page of the package asks for it. Most vessel quotes come down to the same ten families of lines.

Here they are, in the order most estimators build them:

1. Shell plate and heads are the steel for the cylinder and the dished ends, bought by weight in the grade the data sheet names.
2. Nozzles, flanges and small parts cover the pipe or forged necks, the flanges, any reinforcing pads and any stiffeners.
3. Fabrication and welding is the shop's own labour for cutting, rolling, fitting, welding and finishing, priced in hours.
4. Heat treatment covers any post weld heat treatment of the whole vessel and any stress relieving of formed parts such as heads.
5. Nondestructive examination, or NDE, covers radiography and the other checks that find flaws in welds without cutting them.
6. The pressure test is usually a hydrotest, where the finished vessel is filled with water and pressurized above its design pressure to prove it holds.
7. Inspection by others is the time of any inspector the buyer appoints, on top of the inspection the code itself requires.
8. The code certificate and documents cover the nameplate, the certificate, the test reports and the data folder that travels with the vessel.
9. Painting, preservation and shipping cover the paint, the flange covers and whatever protects the vessel on its way to site.
10. Open lines are items the package has not settled yet, and a careful quote shows them as TBD instead of a number.

What sits next to the priced lines

A good draft carries three more things besides the lines. Each one helps the estimator decide, and none of them is a cost by itself.

• Calls are decisions the package leaves open. Each call shows the reading the draft carries and the price of the other reading, so the estimator can see what the choice is worth.
• Questions for the customer are the points nobody inside the shop can answer. They are written so they can be pasted straight into a reply.
• The commercial terms cover validity, delivery and payment. This guide stays on the technical lines, because that is where the package moves the price.

Why the line structure matters

A lump sum cannot be checked. A list of lines, each with its page, can be checked by anyone in the shop, and a missing cost shows up as a missing line.

The page reference is what turns a price into something a second person can review. It also tells you which line to change when an addendum arrives.

The worked example: a draft quote for a Kochi Refinery vessel

The package is a public request for quotation from Engineers India Limited, written for Bharat Petroleum's Kochi Refinery expansion.

Its title is Pressure Vessels CS (up to 25 mm), where CS means carbon steel, and it is dated 10 October 2013.

Its 283 pages hold the covering letter, the instructions to bidders, the job instructions, two EIL standards and the vessel data sheets.

The two standards are the General Specification for Pressure Vessels, 6-12-0001, and the Supplementary Specification for Carbon Steel Vessels, 6-12-0002. Between them they set most of the technical rules the quote has to price.

One caution about the standards

The copy of 6-12-0001 in this package is Rev. 5, dated 30 June 2010, and 6-12-0002 is Rev. 7 of the same date.

A later EIL tender lists Rev. 6 of 6-12-0001, which we could not read in full, so a newer package may say something different.

The EIL pages are scans, so we checked every quoted line against the page image. Every page reference below is the stamp "Page N of 283" printed on each page of the package.

The example draft quote

This is an example draft quote, priced with sample rates. The rates are not any real shop's rates, so read the numbers as a picture of how the lines are built, not as a market price for this vessel.

The sample rate card sets shop labour at $92 an hour, third-party inspection at $1,350 a day and a margin of 25%, with rates as of October 2026. The draft is dated 19 October 2026.

The nine priced lines add up to $147,820.00 plus the TBD line for the level instrument nozzles.

Read the total that way, because a total that quietly drops the held item is lower than the price the package asks for.

The draft also carries one call and three questions for the customer. The call is the spot radiography rule: if the estimator flips it to the other reading, the radiography line rises by $5,800.00 and the total becomes $153,620.00.

How to read the table

• A quantity of "1 lot" means the line is priced as one package of work or material, built from the shop's own breakdown underneath it.
• The welding hours and the inspection days are priced by quantity, because those are the two items the sample rate card prices directly.
• The pages column gives the page stamp for every requirement that set the line, so a reviewer can open the page and check it.
• TBD means the package does not settle the item yet. It is not a zero, and it is not a guess.

What drives each line's price, and where the pressure vessel specification says it

This section takes the ten lines in order. For each one, it says what moves the price and which page of the package sets it.

Shell plate and dished heads: $46,800.00

Plate is bought by weight, so its price follows the thickness, the size of the vessel and the grade. The Kochi package adds two things that raise the weight before anyone cuts steel.

The first is a forming allowance for the heads, set in the instructions to bidders:

On a 25 mm head, 10% is 2.5 mm, which is more than 2 mm, so you buy 2.5 mm of extra thickness for every head.

On a 15 mm head, 10% is only 1.5 mm, so the 2 mm floor applies instead.

The second is the corrosion allowance. The data sheet on page 230 sets 3 mm, which is extra wall added so the vessel can lose metal in service and still be safe.

That 3 mm goes into the plate thickness you buy.

If the vessel has trays or bolted internals, clause 3.2 of 6-12-0001 on page 144 adds the allowance to both sides of tray support rings.

Removable internals other than trays get half of it on each face that touches the vessel contents.

Then there is the grade. The data sheet strikes the words "OR EQUIVALENT" from its material heading on page 230, so the example prices the named grade only.

Whether an equivalent may be offered is one of the open calls below.

A quick way to see what a few extra millimetres do to the plate weight is the metal weight calculator.

Nozzles, flanges and stiffeners: $18,400.00

The nozzle line follows the nozzle schedule: how many openings there are, what sizes and flange ratings they have, and whether each neck is pipe or a forging. Forgings cost more and take longer to arrive.

EIL's carbon steel supplement asks for self-reinforced forged nozzles of 80 NB (3 inch) and above "for equipments where nominal thickness of shell/head exceeds 50 mm". That rule is on page 156 of 283.

A self-reinforced nozzle has a neck thick enough near the shell to replace the metal cut out for the hole, so it needs no reinforcing pad.

This package is for vessels up to 25 mm, so the rule does not apply, and the line is priced without those forgings.

The data sheet adds one small cost that is easy to drop. Its note 9 reads:

Each small nozzle gets two flat bars, welded at right angles, to brace it. That is a little steel and a little welding per nozzle, and it adds up on a vessel with many vents, drains and instrument connections.

If any nozzle is larger than 24 inches, EIL calls for ASME B16.47 Series B flanges on page 145.

Series A and Series B flanges of that size are different forgings with different bolt patterns, so the series on the purchase order must be the right one.

One flange rating is on hold on the data sheet. The draft covers it with a question to the customer, and if the answer comes back a class higher, this line goes up.

Fabrication and welding: 460 hours at $92.00

Labour is the second largest line in the example, at $42,320.00. The hours follow the weight of steel, the length of weld, the number of nozzles and the fit-up work.

The package says plainly that you cannot take the weights from EIL's own drawings:

So the hours must come from your own weight take-off, not from the customer's numbers. If the EIL weight turns out to be low and you priced from it, the missing hours are yours to pay for.

The example carries 460 hours at the sample shop rate of $92.00 an hour.

In a real quote, the hours would come from the shop's own rules, such as hours per ton of shell and hours per nozzle by size.

Those rules usually live in a senior estimator's workbook, or only in their head. We wrote about keeping them inside the company in how to capture estimator knowledge.

Stress relieving of the heads: $6,900.00

This is the line most likely to go missing. The data sheet on page 230 gives post weld heat treatment, or PWHT, as "NIL". The very next line gives heat treatment as "HEAD AS PER SPEC."

PWHT means heating a welded part in a controlled cycle and cooling it slowly, so the stresses left by welding can relax.

The specification that the data sheet points to is EIL's carbon steel supplement, and it says this about heads:

The vessel skips PWHT, but its heads do not. An estimator who reads only the PWHT line leaves out a line worth $6,900.00 in the example, which pays for furnace time, fixtures and transport for the heads.

The draft keeps the line and cites both pages, 157 and 230, so the reviewer can see why it is there.

If your head supplier delivers the heads already stress relieved, the cost moves into the head price, but it still has to be somewhere in the quote.

Spot radiography: $4,600.00

Radiography is an X-ray or gamma ray picture of a weld. Spot radiography means taking short sample pictures along the seams instead of covering their whole length.

The example prices the rule in the job instructions on page 125. That rule asks for one spot of at least 150 mm in each long seam and each round seam, plus one T joint in each round seam.

A T joint is the place where a long seam meets a round seam.

The price follows the number of shots, the film and the technician's time. This is also the line where the package leaves the most money open, which the section on open calls explains below.

Hydrotest: $5,800.00

The hydrotest line pays for the water, the test bay, the crane, the pump and gauges, the test crew's time and the drying afterwards. EIL adds three rules in 6-12-0001, all on page 149 of 283:

• The test water must be clean potable water, and clause 5.6.3 says "Sea water shall not be used."
• Clause 5.6.1 says the water "shall preferably not be less than 16° C", which can mean heating the water in a cold shop or a cold month.
• The same page asks for every vessel to be "thoroughly dried by blowing dry air" after the test.

None of these is unusual. Each one is still a cost, and the estimator should see it on the line instead of assuming it.

Third-party inspection: 8 days at $1,350.00

Third-party inspection, or TPI, means an independent inspection company that witnesses the work and signs for the buyer. For a vendor outside India, the package puts its cost on you:

The example assumes a foreign vendor and carries eight inspector days at the sample day rate, which comes to $10,800.00.

For Indian vendors, the package has EIL do the inspection itself, so an Indian shop would not carry an agency's day rate on this line.

The number of days follows the number of visits. Clause 5.3 of 6-12-0001, on pages 148 and 149 of 283, asks for the inspector's written approval at one stage after another:

• The inspector approves the raw material identification and the edge preparation.
• The inspector approves the rolling, the nozzle setting and the radiography.
• The inspector approves the stress relieving, the pressure test and the painting.

Count the visits from that list and your own schedule, then multiply by the day rate. A percentage of shop hours will not match the way inspection agencies bill.

Code certificate and data folder: $4,900.00

Paperwork is a real cost on a vessel, because someone has to collect, check, copy and bind it.

Clause 9.0 of 6-12-0001, on page 152 of 283, asks for the "Manufacturer's Code Certificate" and a "Rubbing of name plate" in the data folder.

The package adds more on page 121 of 283:

• Radiographic reports must come "WITH FILMS", and the vendor must store them for five years.
• The final documents come as six prints and two CDs or DVDs.

Page 120 asks for the data book within two weeks after dispatch, so the paperwork has to be ready while the vessel is still on the road.

One more cost belongs near this line. Where the Indian Boiler Regulations or India's Static and Mobile Pressure Vessels Rules apply, clause 3.5 on page 144 makes getting the approval the "vendor's responsibility".

Painting and flange covers: $7,300.00

This line holds the paint and the covers that protect the open nozzles in transit. The inspector's stage list on pages 148 and 149 includes painting, so the paint work also needs a signed approval.

For the covers, clause 6.3.1 of 6-12-0001 is specific:

Count the covers from the nozzle schedule, one for each flanged opening. On a vessel with many nozzles, cut and drilled plate covers with their bolts are a noticeable part of this line.

Level instrument nozzles: TBD

The data sheet on page 230 puts five items on hold. A hold is an item the engineer has not settled yet, and one of the five is the size and number of some level instrument nozzles.

The instructions on page 123 still ask you to price them:

The draft does not invent a size or a count.

It shows the line as TBD, with both pages, and turns it into a question for the customer. How to close that TBD before the bid goes in is covered below.

Where the package leaves money open

A package of 283 pages does not always agree with itself. In the Kochi package, three open points can change the price, and each one needs a decision before the quote goes out.

Before deciding anything, check what the bid rules let you do with an open point. The rules decide where your answer is allowed to go.

First, the bid rule decides where an open point can go

The same page says that submitting a price means you have confirmed compliance with all technical specifications.

The covering letter adds that the bid will be evaluated as received and that technical queries may not be issued (page 2 of 283).

Page 3 also says that price changes made against clarifications are not allowed. Put together, these pages mean that every open point has to be asked before the due date, or priced the safe way.

Under this package, you cannot write a clarification into the offer. The calls and assumptions live in your own quote file, and the questions go to EIL in writing before the bid.

Call 1: which spot radiography rule do you price?

The standard, 6-12-0001 clause 5.4.2 on page 149, says that where spot radiography is specified, you radiograph all T joints plus at least 5% of the remaining weld length.

The job instructions on page 125 say that clause "shall be replaced" by a lighter rule.

The lighter rule is one spot of at least 150 mm in each long and round seam, plus one T joint in each round seam.

That would settle it, except that page 143 ranks the documents and says the most stringent requirement governs. Read that way, the heavier rule in the standard still applies.

The draft carries the job instructions, because page 125 says in plain words that the standard's clause is replaced, so that is the likely intent.

It shows the standard's reading beside it as a call, with the radiography line priced at $10,400.00.

If the estimator flips the call, the radiography line rises by $5,800.00 and the total moves to $153,620.00 at once. The estimator sees what the safe reading costs before choosing it.

The question for EIL names both pages and asks which rule to price.

If no answer comes back by the due date, the estimator has to choose, and because a submitted price confirms compliance, some shops will carry the standard's rule and accept the higher number.

Call 2: may you offer an equivalent plate grade?

Clause 2.2 of 6-12-0001, on page 143, allows "Other specifications of equivalent grade" with EIL's written approval. The data sheet on page 230 strikes out the words "OR EQUIVALENT".

The draft carries the named grade only, because the data sheet is the more specific document. An equivalent grade may lower the plate cost, but nobody can say by how much until a mill quotes it.

So the draft books no saving. It asks EIL whether an equivalent may be offered, and because the offer cannot carry technical clarifications, that answer has to come back before the due date.

The holds: items you must price before anyone has drawn them

The five holds on page 230 are the nozzle orientations, the nozzle elevations, the support height, one flange rating, and the size and number of some level instrument nozzles. Each one touches a different part of the quote:

• The orientations and elevations mostly change the drawings and the nozzle layout.
• The support height changes the steel and the welding for the supports, so it touches the plate and fabrication lines.
• The flange rating touches the nozzle line, because a higher class means a heavier flange.
• The level instrument nozzles are new items, so the draft gives them their own TBD line.

Page 123 says the quoted price includes the holds.

So under this package, the TBD cannot stay in the offer you send. Before the due date, it has to become either a firm answer from EIL or an allowance you choose to carry.

A lump sum that includes open holds is a fixed price on things nobody has drawn yet. We wrote about that risk in fixed price contract risk starts at the quote.

The TBD line and the questions for the customer

The example ends with three questions, written so they can be pasted into an email to the customer. Each one says what its answer does to the quote.

Why a TBD is better than a guess

A guess disappears into the total. Nobody reviewing the quote can tell that the level nozzles were priced from a hunch, and nobody remembers it when the real sizes arrive.

A TBD stays visible. The reviewer sees exactly which line is open, which page holds it, and which question will close it.

How to word a question so the answer is usable

• Name both pages, so the engineer on the other side does not have to search for them.
• Give the two readings in plain words, so the answer can be a simple choice.
• Say which reading you priced, so that even a short reply tells you whether your basis is right.
• Ask one thing per question, so one answer does not leave the other half open.

When no answer comes back

Customers do not always answer before the due date. Under EIL's rules, the price you submit is then taken as full compliance, so the estimator has to close every open point inside the price.

For the radiography call, that means choosing a reading and knowing it may cost $5,800.00 more.

For the level nozzles, it means carrying an allowance and writing down how it was built, so the job team knows what was assumed.

How the same quote changes under another owner's pressure vessel specification

The Kochi package is one owner's rule book. To see which lines move from owner to owner, we read three more public documents beside it.

Two cautions about these documents

• The Hanford document is a draft. It is attached to an expression of interest, which is a market research letter sent before a request for proposal, and its Attachments A to D, including the nozzle loads, still say "TBD".
• The Los Alamos section is a master template. Words in square brackets are choices the designer makes for each project, so a real project copy may differ.

Page references follow each document's own printed numbers.

For ADNOC that is the footer "Page X of 141", for Hanford it is the printed body page, and for Los Alamos it is the footer "43 4113 - X of 47" plus the paragraph number.

Which lines move

ADNOC: the NDE line can double

On a heat treated ADNOC vessel, the NDE in the example would be priced twice, once before the furnace and once after it.

ADNOC also asks for ultrasonic testing of shell and head plates from 38 mm thick on a 75 mm grid (page 34), and it accepts only forged flanges (page 18).

ADNOC also handles open points the opposite way from EIL. Its page 14 says that if a quotation carries no list of deviations, the vendor is assumed to comply fully with the specification.

Under ADNOC, a reading you priced that could fall short of the strict one belongs on the deviation list in the quotation, with the price of complying beside it. Under EIL, the same point has to be settled before the bid.

Hanford: the radiography line grows from spot to full

The Hanford draft asks for all Category A, B and D weld joints to be fully radiographed (page 16).

Those are mainly the long seams, the round seams and the nozzle welds, so the example's spot radiography line would become full radiography of every main weld.

The same draft asks for a lifting lug proof test at 200 tons (page 29), which is a hold point followed by dye penetrant testing of the lug welds.

That is a line the Kochi quote does not have at all.

The tank is not code stamped, but the seller must still hold ASME certification (pages 1 and 23). So the code certificate line gets smaller, but it does not disappear.

Los Alamos: a compliant price with an alternate beside it

Los Alamos asks for a base bid in full compliance.

You may also offer an alternate design if it saves money or time, as long as it comes with the base quotation and is clearly noted as an alternate (paragraph 1.7.D.9.a, page 25 of 47).

Under that rule, a cheaper reading of a call can sit in the offer beside the compliant price, clearly labelled, instead of replacing it.

Los Alamos also ranks the rules differently. It says ASME Section VIII and the regulations "will take precedence" (page 8 of 47), while the Kochi package says the most stringent requirement governs.

The same conflict can be priced two ways, depending on whose document it is.

How to check a draft before it goes out

A draft is only useful if someone checks it before it leaves the building. Here is the order we would check the example in, and the same order works for your own vessel quotes.

1. Check that every line has a page. A line with no page is a line nobody can defend when the customer asks why it is there.
2. Add the lines yourself. The nine priced lines in the example come to $147,820.00, and flipping the radiography call adds $5,800.00 for a total of $153,620.00.
3. Check the quantities against your own take-off. Page 123 says EIL's drawing weights are not the basis for the offer, so the plate and the hours must come from your own numbers.
4. Look for the trap lines. The head stress relief must be on the draft even though the data sheet says PWHT "NIL" (pages 157 and 230).
5. Check the service on the data sheet. Clause 4.3.2 of 6-12-0002, on page 157, asks for PWHT of vessels in hydrogen, amine, sour or cyclic service, and clause 4.8.2 on page 148 wants the vessel treated as a complete unit with its skirt wherever practicable.
6. Ask why each missing cost is missing. Forged self-reinforced nozzles and production test plates apply only over 50 mm (pages 156 and 158), and vessel PWHT is "NIL" on page 230, so none of them is a line here.
7. Check the radiography extras. Nozzles rolled from plate and the seams of formed heads need full radiography (clauses 5.4.3 and 5.4.4, page 149), and any conical reducer must be a toricone with fully radiographed seams (clause 3.4, page 144).
8. Check the inspection days against the stage list on pages 148 and 149, and check whether your shop is a foreign or an Indian vendor under page 125.
9. Check each call. Make sure the reading carried is one you would defend, and that its question has gone to the customer.
10. Close the TBD. Under page 123 the price must include the holds, so the level nozzles need an answer or an allowance before the bid goes in.

A toricone, in item 7, is a cone with a curved knuckle at each end where it meets the cylinder, instead of a sharp corner.

EIL wants the knuckle radius to be at least 10% of the adjoining diameter, which adds forming work as well as radiography.

A list like this is easier to keep in a spreadsheet, with one row per requirement and columns for the page, the line it feeds and the price. Our specification compliance matrix template is set up that way.

To turn the open points into a register the whole team can see, read pre-bid risk assessment.

How Mavlon's AI Quoting Engine produces this kind of draft

Mavlon's AI Quoting Engine does the work this guide describes. A bid package goes in, and a priced draft quote comes out in the manufacturer's own pricing, ready for the estimator to review.

It prices the way your company prices

The engine learns each company's pricing from that company's own past bid packages, the quotes it sent, and its costing workbooks and rate books.

The hour rules, the rates and the margin on the draft are the company's own, not a generic price list.

That also keeps the pricing consistent when a senior estimator is away, because the rules come from the company's own past work and not from one person's memory.

What the draft contains

• Every line has a quantity, a unit price and an amount, and it keeps the page it came from.
• Lines the package does not settle say TBD instead of a guess, like the level instrument nozzles above.
• Decisions the package leaves open become calls with the price of each reading, and flipping a call moves the total at once.
• Anything nobody can answer becomes a question for the customer, ready to paste into the reply.

What stays with the estimator

The estimator checks the draft, changes what they know better, and sends the quote. The engine does not decide whether the shop complies, and it does not set the final price.

For a vessel shop, the gain is that the same estimators can quote more bids. The first draft takes minutes instead of days of reading, so the estimator's time goes into the calls and not into the page turning.

How it is tested

The example in this guide is priced with sample rates, so it shows the shape of a draft, not a real shop's number.

On a real account, the test is blind: the engine prices the company's own past bid packages, and its totals are compared with the quotes the company actually sent.

The pass bar is agreed in writing before the test starts. The protocol is on our pilot page, where the published bar is 7 of 10 job totals within 15% of the filed quote.

For a wider view of what to ask of any tool like this, see our AI quoting software buyer guide.

Sources

• Engineers India Limited for Bharat Petroleum Corporation, RFQ SM/A307-IC-VV-MR-6007/59, Pressure Vessels CS (up to 25 mm), Kochi Refinery, dated 10 October 2013. It contains General Specification for Pressure Vessels 6-12-0001 Rev. 5 and Supplementary Specification for Carbon Steel Vessels 6-12-0002 Rev. 7, both dated 30 June 2010.
• Abu Dhabi National Oil Company, Pressure Vessel Specification, AGES-SP-06-002, Rev. 1. No printed date; the file was created in October 2021.
• Hanford Tank Waste Operations and Closure for the US Department of Energy, Pretreated Waste Storage Tank (PWST) Specification, RPP-SPEC-67201 Rev. A, a draft attached to the expression of interest dated 21 January 2026.
• Los Alamos National Laboratory, Master Specification Section 43 4113, Gas and Liquid Pressure Vessels, Rev. 2, 29 January 2025.