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Universal Coupling Installation Guide

Installation instructions for AQUAFITTING Universal Couplings, with seal-handling photographs, tightening notes, setting-gap references and the size table.

DN40–DN600AQF-IG-UC-001Revision R3 · 03 October 2026

Preparation and alignment

Universal Couplings are supplied ready assembled. It is not necessary to dismantle the product for installation.
AQUAFITTING Universal Coupling.
AQUAFITTING Universal Coupling.
  1. Examine both pipe ends

    Ensure the pipe ends are round, smooth and free from bulges, dents, score marks, scale, rust and loose debris. Check that both pipe diameters are within the range provided for the coupling. Weld beads must be ground flush while maintaining the correct surface profile.

  2. Check the gasket and lubrication

    Check that the grade of gasket is suitable for the conveyed medium. Check that the rubber seal is sufficiently lubricated where it contacts the coupling centre barrel. If not, apply a suitable lubricant.

  3. Align, support and mark

    Align the pipe to be laid with the pipe already in position. Keep the pipe ends concentric, adjusting the support or trench bed as necessary. Mark both pipe ends at a distance equal to or greater than half the overall assembled width of the coupling. Place the coupling wholly on one pipe end.

Cleaning the seal.
Cleaning the seal.
Applying suitable lubricant.
Applying suitable lubricant.
Checking the assembly.
Checking the assembly.

Tightening and setting gap

  1. Centre the coupling

    Adjust the setting gap between pipe ends as necessary. Using the marks made in Step 3, slide the coupling to a central position over the pipe ends and commence bolt-up.

  2. Tighten opposite bolts progressively

    Tighten diametrically opposed bolts, giving the nuts one or two turns at a time to draw up the end rings evenly. Tighten to the specified torque, working around the coupling as many times as necessary. The radial gap between the pipe and coupling should be even all the way round. Rubber may be seen to extrude.

Bolt torque rating

Bolt sizeTorque (Nm)
M1270–80
M1490–100
M16100–120

Tighten in diametrically opposite pairs. The source torque section specifies 2 or 3 turns per pass; installation Step 5 specifies 1 or 2 turns. Confirm the applicable tightening procedure for the supplied assembly.

Setting gap reference

Coupling DN (mm)Sleeve width (mm)Recommended gap (mm)Max. gap (mm)
Up to DN2001001632
Over DN250 – DN7001602040
Over DN700 – DN16002002040

The source gap table extends beyond this guide’s stated DN40–DN600 size range and leaves the interval above DN200 through DN250 unclear. Its sleeve widths must not be equated automatically with the L column in the size table. Confirm the applicable row and pipe-end gap for the exact coupling.

Size reference

Size and range reference

SIZERANGEALLQty
DN4048-63165100M12*1802
DN5059-7218095M12*1802
DN6572-8518095M12*1803
DN8088-10319095M12*1804
DN10093-11720095M12*1804
DN100107-12821495M12*1804
DN125138-15325095M12*1804
DN150155-175278105M12*2004
DN150159-182278105M12*2004
DN175192-210300130M12*2204
DN200218-235324130M12*2204
DN225250-267406130M12*2306
DN250235-252406130M12*2306
DN250271-289440130M12*2306
DN300315-332452130M12*2306
DN300322-339463130M12*2306
DN300324-350510165M12*2306
DN300345-375510165M12*2306
DN350374-391510165M16*2508
DN400400-429560165M16*2508
DN400417-437560165M16*2508
DN400455-472560165M16*2508
DN450480-500560165M16*2508
DN500500-535560165M16*2508
DN500526-546630165M16*2508
DN500555-572700165M16*25010
DN600600-630700165M16*25010
DN600630-650700165M16*25010

Both L headings are retained as printed. The first L column contains numeric values; the second contains bolt designations such as M12*180. Do not treat them as the same dimension. Confirm the current drawing, symbols and units before dimensional use.

Universal Coupling section drawing. Confirm the L and A references for the selected assembly.
Universal Coupling section drawing. Confirm the L and A references for the selected assembly.
AQUAFITTING · Installation GuidesAQF-IG-UC-001 · R3 · 2026-10-03
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