Isometrics, a line list and a piping specification, read into one draft spool quote sheet for your estimator.

A bid set reaches your estimator in pieces: a folder of isometrics, a line list or piping schedule, the piping specification, and general notes on coating, testing and inspection. Your estimator walks each isometric, counts pipe, fittings, flanges and welds, looks up the class for that size, reads what the specification wants for examination and finish, and notes anything that doesn't line up, all before a single rate goes on the page.

In the test, AI reads copies of those documents and drafts the spool quote sheet: line number, size and schedule, material and class as stated, fittings and welds by count, the examination requirement named in the specification, coating or lining, and the page each entry came from. Where an isometric and the line list disagree, both values appear and the line goes on a list for a person to resolve. No rate is applied and no price appears.

The list goes by several names, and sometimes it's a table on a drawing. Projects call it a line list, a line index, a line schedule or a piping summary: one row per line with pipe class, nominal size, insulation, test medium and pressure, a post-weld heat treatment flag and an examination level. A line number can string together size, sequence, fluid code, area, class and insulation in whatever order that project chose. Water work may skip the list altogether. New York State's 2024 master specification for plant water piping lets systems be defined on the drawings by a piping schedule, and one of its pressure testing options reads simply as indicated in pipe schedule. The draft records which document supplied each field, so a schedule and a list can't quietly disagree.

An isometric is drawn without scale, then cut into spools. The picture doesn't measure anything; the dimensions and the bill of material do. The title block carries line number, class, design conditions, insulation and paint, and one isometric becomes several spools depending on what can ship and where a field weld or a flange makes a sensible break. Move that break and a shop weld becomes a field weld. Vista Irrigation District and the City of San Diego both make steel pipe shop drawings distinguish between the two. The draft counts shop and field welds separately, by weld number where the isometric gives one.

A branch or a size band can be settled by a table. The University of Iowa's plant standard ends in a branch table, header size across and branch size down, answering each crossing with a standard tee, a reducing tee, a socket outlet or a weld outlet. Its 2021 revision moved 2-inch branches to socket outlets and an 8-inch branch on a 24-inch header to a weld outlet. Its stainless condenser water sheet takes Schedule 40S socket weld or threaded at 2 inches and smaller, flanges not permitted, then Schedule 10S butt weld through 48. New York's stainless section leaves a bracket for whether field welding is allowed at all. Each of those changes the fitting and the weld on the line, so the draft shows which row of which table it read, and an unfilled bracket goes on the list.

Examination is a field, never a default. A line list may give one examination level and the specification another, and the extent is whatever that project's specification sets, so the draft copies the method and the wording and offers no figure of its own. A 2021 sample specification from New York's State University Construction Fund, for high pressure steam, has the owner's agency perform the examinations and puts the cost of retests after a failed weld on the contractor. Two water agencies working from AWWA C200 differ on production weld tests: Vista adds one every 2,000 feet of production weld, San Diego every 5,000, and San Diego also on a change of welder. We repeat these for recognition only, as neither legal nor engineering advice. What a requirement costs is for your estimator to decide.

Coating and lining set the order of work. New York's steel process pipe section has cement-mortar lining shop-applied after fabrication under AWWA C205, points to C210, C213 and C222 for other coatings, and calls for an electrostatic spark test on each plastic-lined pipe. Vista and San Diego keep outside coating off a seam until it has been tested. Kentucky's boiler regulation says piping connected to a boiler, welded joints included, isn't painted or covered before inspection. A note on the isometric can say one thing and the specification another. The draft carries each finish as stated and lists the conflict. Your reviewer, usually the chief estimator, checks every count, class and conflict against the sheet your team built.

With your reviewer's yes, new bid sets get the same reading for about 30 days.

Your estimator approves every quote sheet, settles every conflict and applies every rate. Questions for a customer leave from your office. Another job carries a price of its own, with monthly support after that.