Viking Johnson MaxiDaptor Flange Adaptor DN50-DN300

A flanged connection for plain-ended pipe without welding

The Viking Johnson MaxiDaptor joins a plain pipe end to a flanged valve, pump, meter or fitting. A ductile iron adaptor body with an integral drilled flange sits over the pipe, a gasket seals on the pipe OD and the end ring is tightened with M12 bolts. Like MaxiFit it is a wide-tolerance design, so DN50 covers 57 to 74 mm OD pipe and DN300 covers 315 to 349 mm.

The flange side is drilled to PN10/16 as the base specification, with the datasheet also listing ANSI 125/150, BS10 Table D/E, AS 2129 Table D and E, AS 4087 PN16 and AWWA C207 Class D options for selected sizes. The datasheet makes one point clear: the drilling pattern matches those standards, but the rated working pressure remains the product rating of 16 bar for water.

MaxiDaptor technical specification

Dimensions from the datasheet (sizes and pipe OD range in mm; M = maximum flange diameter; S = bore; L = overall length; A x T = sleeve length x thickness; the matching flange drilling includes PN10/16; weight in kg).

Features and what the drilling table means

• Setting gap of 20 to 25 mm minimum and 40 to 60 mm maximum, depending on size, so installation tolerances can be absorbed.
• Larger sizes list several drilling options in the same body, for example DN100 with PN10/16, AS2129 Table D, AS4087 PN16, BS10 Table E, AWWA C207 Class D and ANSI 125/150 as listed.
• A MaxiFit Plus threaded-outlet version is available on selected sizes (marked in the datasheet).
• Same Nylon 11 coating and approvals as the MaxiFit coupling range.

Selection and ordering guide

Start with the pipe OD you measure, then the mating flange standard. For example, a DN100 line meeting an ANSI 150 valve uses the DN100 adaptor with the ANSI 125/150 drilling, while the same body drilled PN10/16 suits a European flange. Remember that a drilling match does not change the pressure rating: even with an ANSI flange pattern the adaptor is rated at 16 bar for water. Choose the gasket by medium, EPDM for water or nitrile for gas, and consider stainless fasteners for wet chambers. Since the adaptor takes no end load, the datasheet calls for the line to be held externally, with tie rods across the adjoining flange or anchors.

There is no single product code printed, so an enquiry should name the size, drilling standard, gasket and fastener material for the maker to confirm.

Installation notes

• Draw the M12 bolts up to the 55-65 Nm range with a 19 mm spanner.
• Restrain the line externally, as the adaptor does not carry end thrust from line pressure.
• Accommodate no more than 3 degrees of angular misalignment on a flange adaptor at maximum pipe OD.
• Where service temperatures exceed 60 C, expect to re-torque the bolts later, as the datasheet notes.

Typical uses in Oman and the GCC

Flange adaptors are the usual way to tie a valve chamber, a pump suction or a meter run into existing plain-ended pipework. In pumping stations, desalination post-treatment and district water networks the adaptor lets a site crew fit a flanged valve without cutting threads or welding. The datasheet limits are -20 C to +90 C and 16 bar water, so confirm hot-service conditions and any fluid other than water or gas with the maker.

Selection and installation notes

Pipe couplings and clamps must be chosen from the actual pipe outside diameter, the pipe material, the working pressure and the joint movement expected, so measure the pipe before ordering and compare the reading with the size range on the data sheet. Clean the pipe surface and remove dirt, scale and sharp edges, mark the insertion depth, centre the coupling over the joint and tighten the bolts evenly in a cross pattern to the torque in the installation instructions. Check the joint again after the line has been pressurised, and do not use a coupling outside its stated pressure rating.

A flange adaptor must be matched to the flange pattern of the valve or pump, so confirm the drilling standard and pressure class before ordering.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related items and documents

Pair the adaptor with MaxiFit couplings; more fittings are in our pipes and fittings category. The datasheet can be downloaded from this page, and Seven Star LLC can quote against your size and drilling list.