--- title: Choosing a product — materials and special lines description: How corrosion, wetted materials and linings are chosen, and how lines outside range, excluded lines, plastic lines and reviewer picks are treated. sidebar: label: Choosing — materials and special lines order: 9 --- 11 rules, in register order, from R30 to R96; numbers do not run in sequence. [Back to the index](/business/business-rules). ## R30 — A severe corrosion band excludes only when the fluid is not mild overall Water rates carbon steel at the worst letter yet is a mild fluid; carbon steel is Flowtech's standard build for its most common application. ## R31 — A measured corrosion rate may condemn a material the chart cleared, but may not clear one the chart calls severe A measured rate is blind to pitting and stress cracking. ## R79 — A wetted part the enquiry leaves blank takes a material the fluid's grades allow, where it can On a header the fluid touches, with no material stated and none decided by a mapping, a process condition or another header, each option takes the grade of the material it names, so SS 316 sheet and SS 316 pipe grade alike. The default stays when the line's fluid grades it A or B, or D for a fluid that is mild overall (R30); otherwise the first option in datasheet order graded A or B is taken, Custom and not-applicable options aside. An option that would refuse a header the enquiry states is never kept or taken (R78). Where no option is graded A or B, or every one that is would refuse a stated header, the header keeps its default or only option and says so. Where its options name materials but the line has no fluid from the library, only a guessed one, or one the chart grades none of them for, it keeps them and says the material was not checked. A header whose options name no material, such as a connection type, or that is set to a not-applicable option, is left alone and says nothing. A header with two defaults takes the one the fluid allows when exactly one is graded A or B, or D for a mild fluid, and is otherwise left for a person (R77). A hard limit can still reject the fluid's pick (R62); the header is then answered as R77 says, and the next graded option is not tried. R93 may then change an end connection for the material of the line's pipe. ## R89 — A lining the enquiry leaves blank follows the metal the fluid would touch A lining header is one the fluid touches that offers a "Not Applicable" option, meaning unlined, such as the metal tube rotameter's LINER MOC. It is decided after the other wetted headers (R79). Where every material those headers leave in contact with the fluid is graded A or B, or D for a fluid that is mild overall (R30), the instrument is unlined. A material in contact that the fluid's chart does not grade, such as carbon steel against sodium chlorite, leaves the lining at its default, saying which material was not graded, unless another material fails. The end connection it grades is the one R93 leaves. Otherwise it takes the first lining in datasheet order graded A or B, and its flow table follows the lining, so a lined tube is sized on the lined table (R29). Where no lining is graded A or B the header keeps its default and says which metal failed; where the fluid has no grades it keeps its default and says the lining was not checked. A stated lining always stands, and a hard limit can still reject the pick (R62). A new lining material is set up on the datasheet alone: the chart must grade it for the fluid to be chosen. ## R92 — A line asking for a product Flowtech does not make is outside range A line is outside range when the start of a cell naming its item or type (the cells R25 reads) names a product on the outside-range list: today a glass pot assembly or an RF admittance instrument, even when a family Flowtech makes is part of it. Only the start counts: the words after "with", "for", "suitable" and the like name what the item is fitted to, so a level switch for a glass pot is not outside range, and neither is a glass pot level switch, which is our instrument. A cell that offers an alternative or a negation ("or", "/", "not", "instead", "replacing") is left for review, never excluded. The line is excluded automatically with the reason and no product is suggested for it. Only a person's Exclude or Confirm clears the mark; confirming reopens the line, and excluding it again leaves their reason alone. Editing the line's fields keeps the mark. The other lines are quoted as usual. An enquiry whose every line is outside range reads Regret on the board. The list is catalogue data; vibrating fork switches are not on it, because Flowtech trades them. ## R112 — A line the client marks deleted, on hold or supplied by others is excluded with the client's words A line is excluded automatically when its row's remarks, status, note or comment column says only that the client does not want it quoted: deleted, cancelled, dropped, withdrawn or not required; on hold or awaiting the client's confirmation; or in the vendor's or the client's scope, by others, free issue or existing. Nothing else may stand beside the status but connecting words, who said it, a row number, a revision or a date. A remark that says more, such as "Changed type to vortex, by client", "Existing reactors, pressure and flow need to be confirmed", "Indicator not required" or "Not deleted", leaves the line in review, and so does such wording in any other column, such as "Drain valve: Not required". The reason is "Client:" and the remark as written, such as "Client: Deleted", and it is given before R92's when both apply. As with R92, only a person's Exclude or Confirm clears the mark: confirming reopens the line, and excluding it again leaves their reason alone. The quotation skips the line with that reason, and a line excluded only by its remark does not count toward Regret on the board. "Vendor's scope" is read as someone else's supply, so where a client means Flowtech by it, a person confirms the line. ## R90 — A text, number or range row the enquiry leaves blank shows the product's datasheet default For the family a line's product suggestion picks, a row of its datasheet that takes text, a number or a range, and that nothing the enquiry states fills, shows the datasheet's default, marked Default, as a menu's default does (R77). A value the enquiry states always stands (R78), so a default never replaces what the customer asked for and is never a deviation (R35); it does not stop a line confirming itself (R71). A default that only says the value comes later, such as "After receipt of PO", and a range the datasheet bounds at one end only, are shown as the datasheet's note under the row, not as a value. Nothing is saved: the default follows the product if it changes. A row the product takes from Flowtech, or that Flowtech supplies after the order, is not a default; it follows R122. ## R122 — A field Flowtech provides is never read from the enquiry Each text, number or range field of a product's datasheet has a source, set on the product's **Fields** list in Product Limitations: **Buyer**, the default, for what the customer asks for; **Flowtech** for what the product provides, such as its rated maximum pressure, rangeability, a description of its construction, or the Flowtech flow range; **After order** for what Flowtech's engineers work out once the order is confirmed, such as an orifice plate's bore, beta ratio and DP. Requirement gathering reads only Buyer fields from the enquiry. A field every product of the category marks Flowtech or After order is never offered to the reading, so a column in the enquiry named after it fills nothing. Nothing works one out from the enquiry either: no bore, beta ratio or DP is calculated. On a line's datasheet, a Flowtech row shows Flowtech's value, marked **Flowtech**, and an After order row shows **After order**, also on a line no product fits yet. Neither can be edited, neither is ever Missing, and neither is asked of the customer. Where the enquiry did state a figure for such a row, it is kept on the line and shown beside the row as "Enquiry states: …", never as the row's value. A Flowtech figure can be held in Product Limitations and linked to the field it is for, as a **Specification** or on an existing limit such as a rated maximum pressure; that figure is then the row's value and its datasheet default is not shown. **Accuracy** is one such figure: the datasheet's Accuracy row is the accuracy the customer asks for, a Buyer field, and Flowtech's accuracy is the product's Accuracy specification, shown beside it and never written into it (R123). ## R91 — A value stated for a row lands on the product's row, whatever key another product files it under Products of one category can name one datasheet row differently, such as "Op. Press" on one and "Operating Pressure" on another. A value the enquiry states for that row is read on the picked product's own row, for its menus, its defaults and the review alike, when the catalogue records the two as the same row. Where the product has the row under the very key the enquiry used, that value is the one read. A product with no end-fitting row of its own, such as the bypass metal tube rotameter, whose connections are on the main line, reads a stated end connection on its main connection row. A product that has one, such as the bypass glass tube rotameter, keeps the two apart. A bypass rotameter, glass or metal tube, has no valve row of its own, only the isolation ball valves on its bypass line, so it reads a stated valve or isolation valve material on its ball valve row. The acrylic body rotameter's valve row is its needle valve and never takes a ball valve material. A line no product fits is laid out by the datasheet of the product the enquiry names, or else by the rows its category's datasheets share. ## R93 — A plastic line steers its end connection to a material that suits it The material of the pipe the instrument is fitted to, its line MOC, is read from the enquiry and sorted into metal, thermoplastic, FRP or lined; wording that names two classes, such as "CS/PP", is sorted into none. It is decided after the wetted materials (R79) and before the lining (R89). Which end-connection materials suit which line material is held as configuration. As shipped, a thermoplastic line prefers a thermoplastic end connection, an FRP line prefers FRP and then thermoplastic, and a metal or lined line places no condition. An end connection the enquiry leaves blank and that is not already on a preferred material takes the first option in the preference order that is not Custom or not applicable, would refuse no header the enquiry states (R78), and is not graded below B for the fluid, so the fluid's grades still apply (R79). Where no option suits, the header keeps the material R79 chose and says so, and the line waits with that item open. A line whose pipe material has such a rule is left awaiting review, so this pass decides it. The caution is worked out from the settled datasheet, so it names the option the header finally holds. An end connection the enquiry states always stands, with a caution when its material does not suit the line. Any other end connection the settled datasheet leaves on a material that does not suit the line takes the same caution, whether the fluid's grades (R79), a "Decided by" rule from the datasheet or an inherited material put it there; one the size fixes or the product switches off takes none. The caution holds the line, listed under **Choose**, except where the enquiry stated the value, the reading matched it to a menu option, it is Custom or a person chose it, which make it a notice. The line's material is shown on the line. ## R94 — On a thermoplastic line, a bare size that is a standard outside diameter, and not a nominal bore, is read as the outside diameter Thermoplastic pipe is sold by outside diameter, so a main line or process connection size of 225 on an HDPE line is a 225 mm pipe, which is 200 NB. The line is sized at 200 NB, the size reads as an assumption, so a limit it breaches only cautions, and the line says "225 read as a plastic pipe outside diameter: 200 NB". The diameters read are 63, 75, 90, 110, 140, 160, 180, 225, 280, 315, 355, 560 and 630 mm. A number that is both an outside diameter and a nominal bore, such as 50, 150 or 200, stays a nominal bore. A size written with a unit, such as "225 NB" or "225 mm", and a size a person entered are read as written. This applies to thermoplastic lines only: PVC, CPVC, HDPE, PP and the other materials R93 sorts as thermoplastic. An FRP or lined line is read as written. A size written as an outside diameter, such as "225 OD", is read by R106 on any line. ## R96 — A reviewer's family choice is kept beside what the enquiry asked; a choice outside the families asked for is a deviation A reviewer picks a family with **Use this instead** on one of the options listed under **Why this product**, and clears the pick with **Use the suggestion**, which returns the line to what it suggests. The pick is saved with who made it and when, and the families the enquiry named stay as stated. Saving it returns a confirmed line to review, as any edit does. The picked family leads the list, is checked and sized as any other, and what would rule it out is kept as cautions, not as a reason to drop it. A pick inside the families asked for is read as the family fitting. A pick outside them is a deviation (R26), with the reason "Chosen in line review" when the pick alone causes it, and the line asks only for the inputs the picked family needs. The quotation prints each limit the picked family was chosen past among the line's notes. A pick from another category is refused. On an accessory line (R27) the family is picked by item code or from the families the line names, not from a ranked list; the line stays not ranked, and the picked family is the only one listed. A pick of a family that is no longer in use is kept on record, but the line shows the suggested family until another is picked (R27).