Technical register · 12 memos on file

The insights register.

Every memo answers one procurement question, in writing, with the standards named and caveated.

ANSWER

Insights is NF Teguh's library of practical valve articles: what testing standards actually verify, how material certificates differ, how to choose between valve patterns, and what nameplate markings mean. Each piece answers one procurement question in plain language so a buyer can specify with confidence. New articles are added as questions come in from Malaysian plants, contractors and purchasers.

GUIDES

Start here: the two guides

Two longer pieces anchor the register. One walks specification from line conditions to a purchase order; the other walks the paperwork — certificates, test reports and markings. Every memo below hangs off one of them.

REFSUBJECTFILED

MEMO-01 Specifying industrial valves: from line conditions to purchase order 2026-08-19 Specifying an industrial valve means turning line conditions into an unambiguous purchase order: fluid, pressure and temperature first, then valve type, pressure class, body and trim material, end connection, operator, and the testing or certificates required. MEMO-02 Valve procurement documentation: EN 10204 certificates, API 598 testing and MSS SP-25 marking 2026-08-19 Valve procurement paperwork answers three questions: what material is this — EN 10204 certificates; was it tested — API 598 reports; and what am I looking at — MSS SP-25 markings.

MEMOS

Technical memos

Filed as questions come in from Malaysian plants, contractors and purchasers — testing, certification, pattern selection, markings. Each is a few minutes' read and ends at what to state on the enquiry.

REFSUBJECTFILED

MEMO-03 Fire-safe valves: API 607 vs API 6FA and when a spec asks for them 2026-08-19 Fire-safe means a valve keeps a defined degree of shutoff after a standard fire test, not that it is fireproof. MEMO-04 NACE MR0175 and sour service: what it means when a valve line names it 2026-08-19 NACE MR0175, now paired with ISO 15156, limits materials for sour service — hydrocarbon streams carrying hydrogen sulphide — because sulphide stress cracking breaks susceptible steels. MEMO-05 What OS&Y means and why rising-stem gate valves dominate isolation duty 2026-08-19 OS&Y stands for outside screw and yoke: the gate valve's stem threads run in a yoke outside the pressure boundary, so the threads never touch the process fluid and the rising stem shows open or shut at a glance. MEMO-06 Specifying pressure class: what Class 150, 300 and 600 actually mean 2026-08-19 Class 150, Class 300 and Class 600 are not working pressures. MEMO-07 EN 10204 3.1 vs 3.2 certificates: what procurement actually needs 2026-08-19 EN 10204 defines material document types, and the practical choice is between type 3.1 and type 3.2. MEMO-08 API 598 valve testing explained: what a shell and seat test report shows 2026-08-19 API 598 is the inspection and testing standard most valve purchase orders cite. MEMO-09 Trunnion or floating: choosing a ball valve mounting 2026-08-19 In a floating ball valve the ball is held only by its seats, and line pressure pushes it onto the downstream seat — simple and economical at small sizes and moderate classes. MEMO-10 Wafer, lug or double-flanged: choosing a butterfly valve body 2026-08-19 Wafer butterfly valves clamp between line flanges and are the lightest and cheapest; lug bodies carry threaded inserts so a line can be dead-ended or dismantled on one side; double-flanged bodies bolt independently to each flange and suit larger sizes and critical or buried service. MEMO-11 Check valve types: swing, dual-plate and piston — where each fits 2026-08-19 Swing, dual-plate and piston check valves all stop reverse flow but behave differently. MEMO-12 Reading a valve nameplate: MSS SP-25 marking explained 2026-08-19 A valve nameplate marked to MSS SP-25 identifies the valve: manufacturer, size, pressure class or rating, body and trim material grades, and often the governing standard and heat identification.

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