Beijing DB11/T 2382-2024: determining chapter by chapter and material by material whether pipe installation quota line items include pipe fittings (gas piping: only galvanized steel pipe with threaded joints includes fittings; indoor water supply/drainage and heating piping include fittings)

Topic Positioning

Within Chapter 6.10 "Water supply and drainage, heating and gas works" of the general installation works volume of Beijing DB11/T 2382-2024 "Construction Consumption Standard": the rules for determining whether a pipe installation quota line item includes the installation of pipe fittings (and pipe clamps). The core is two opposite readings: gas piping is differentiated by material (only galvanized steel pipe with threaded joints includes fittings), while the installation items of indoor water supply, drainage, heating and air-conditioning water piping include the fitting installation content.

Core Conclusions

1. Gas piping (Chapter 6.10, Section IV "Gas piping"): only galvanized steel pipe (threaded joints) includes fittings and pipe clamps; all other materials must follow separate items.

Clause 6.10.34 reads: "The construction consumptions for installation of galvanized steel pipe (threaded joints) shall include the work content of fittings and pipe-clamp installation; for pipes of other materials, the installation of fittings and pipe clamps shall follow the corresponding fitting and pipe-clamp installation items."

Material-by-material application (with the Appendix C line items):

• Galvanized steel pipe (threaded joints): the pipe installation item includes fittings and pipe clamps - no separate item. Example item C10-3-78 (nominal diameter up to 20 mm, unit of measurement m): the work content includes "pipe cutting, threading, pipe and fitting installation, thread painting, pipe-clamp installation, purging, strength test and tightness test"; the materials include galvanized steel pipe 1.0200 m, gas steel fittings 1.0240 pieces/m and clamps 0.7440 pieces/m.
• Welded steel pipe: the pipe item excludes fittings; the fittings follow the steel fittings (welded) items. E.g. C10-3-102 (outside diameter up to 38 mm, unit of measurement "piece"): main material gas steel fittings 1.0100 pieces/piece; the work content includes "argon-arc root runs, welding".
• PE gas pipe (polyethylene pipe): the pipe item excludes fittings. E.g. C10-3-31 polyethylene pipe laying (electrofusion joints) DN50: the materials are only plastic pipe 1.0200 m etc.; the work content is "pipe installation, purging, strength test, tightness test" with no fittings; the fittings follow the polyethylene fittings (electrofusion) items (e.g. C10-3-64: PE fittings 1.0100 pieces/piece) or the corresponding (butt-fusion) items.
• Steel-skeleton plastic composite pipe: falls under "other materials" in the second half of 6.10.34, the fittings following the corresponding "fitting and pipe-clamp installation" items. Note: in this standard, the steel-skeleton plastic composite pipe items are placed in the outdoor water-supply chapter (C10-1-93 etc., electrofusion joints), where the pipe item's work content includes "pipe and fitting installation" and the fittings are carried in the materials at 0.2810 pieces/m - different from the gas chapter, and the chapters must not be applied across; where a gas project meets this material, the applicable items must be re-checked against the design / cost basis.

2. Measurement rules (gas chapter 6.10.36, 6.10.37)

Pipe installation quantities "shall be calculated as the length of the design-shown pipe centreline, without deducting the lengths occupied by fittings, valves and accessories"; "fitting installation quantities shall be calculated as the design-shown number" (unit of measurement "piece") - the pipe is measured over its full length and the fittings counted separately by number, without mutual deduction.

3. Indoor piping (Chapter 6.10, Section III "Indoor piping") runs the opposite way: the pipe installation items include the fitting installation content.

Clause 6.10.32 reads: "The construction consumptions for pipe installation shall include the fitting installation content; the fitting material quantities may be calculated as the design-shown quantities, or as stipulated in Table 6.10.32." Example: indoor steel pipe (welded) C10-2-27 (nominal diameter / outside diameter up to 100/108 mm, unit of measurement m), the materials include steel fittings 0.3600 pieces/m. The same welded steel pipe: fittings included under the water supply/drainage and heating chapters (indoor piping), excluded under the gas chapter - fix the chapter's reading before applying items.

4. Associated rules (gas chapter 6.10.35)

The fabrication and erection of pipe supports, clamps and hooks follow clauses 6.10.39-6.10.42; gas leak-detection pipe installation follows the corresponding pipe installation items; tracer-wire installation follows the warning-tape installation item.

Applicable Boundaries

• These determination rules follow the Beijing DB11/T 2382-2024 basis; the quota manuals / consumption standards of other provinces and cities must be checked separately.
• The gas piping (6.10.34) and indoor piping (6.10.32) readings are opposite - confirm the chapter before applying items; the fittings and clamps of gas "other-material pipes" are listed separately under the "fitting and pipe-clamp installation" items and must not be double counted merely because the pipe item's work content contains the words "pipe installation".
• The main-material quantities of the fitting items include wastage (e.g. 1.0100, 1.0240 pieces/piece); pipes are measured by the centreline length without deducting the lengths occupied by fittings, valves and accessories - do not deduct again at preparation.
• No dedicated pipe item for steel-skeleton plastic composite pipe is seen in the gas chapter; the applicable basis must be re-checked; the outdoor water-supply items for this material (work content including fitting installation) must not be used directly for gas works.
• The Appendix C items are size examples; in execution, take the values of the corresponding sizes in the main text of the standard.

Further Reading

• DB11/T 2382-2024 Chapter 6.10 "Water supply and drainage, heating and gas works": 6.10.32 (indoor piping includes fittings, and measurement), 6.10.34 (gas piping - the fittings determination), 6.10.35 (supports, clamps, leak-detection pipe, tracer wire), 6.10.36 (pipe measurement), 6.10.37 (fitting measurement).
• Appendix C, general installation works, relevant line items: galvanized steel pipe (threaded joints) installation (C10-3-78 etc.), polyethylene fittings (electrofusion) (C10-3-64 etc.), polyethylene pipe laying (electrofusion) (C10-3-31 etc.), steel fittings (welded) (C10-3-102 etc.), indoor steel pipe (welded) (C10-2-27), outdoor water-supply steel-skeleton plastic composite pipe (electrofusion) (C10-1-93 etc.).
• Verification method: compare the "work content" column and the "materials" column of the pipe installation item - where the materials column contains fitting main materials and the work content contains "fitting installation", the fittings are not applied separately; otherwise the corresponding fitting installation items must be applied.