NAFFCO NDR 098 Oblique Landing Valve, Flanged Inlet (BS 5041)

Overview

The NAFFCO NDR 098 is an oblique-pattern fire hydrant landing valve with a flanged inlet, manufactured to comply with BS 5041 Part 1 for installation on wet risers in buildings that are permanently charged with water from a pressurised supply. Its outlet is a delivery hose connection with blank cap complying with BS 336:2010, and the valve is classified as a low pressure landing valve for nominal inlet pressures up to 15 bar. The NAFFCO NDR 098 has a DN50 inlet flange, and the same datasheet covers the NDR 100 with a DN65 inlet flange; NAFFCO lists the range as BSI Kitemark and LPCB certified, with the NDR 100 marked as Kitemark approved.

Seven Star LLC supplies the NAFFCO NDR 098 and NDR 100 to fire protection contractors, consultants and building owners in Oman, with engineering support in Muscat. For anyone searching for a supplier of landing valves in Muscat, these BS 5041 oblique landing valves are among the most widely specified hydrant outlets for wet riser systems in residential towers, hotels, hospitals and commercial buildings.

Operating Principle

A landing valve is the hydrant outlet that firefighters connect to on each floor of a building with a rising main. In a wet riser the pipe is kept full of water under pressure at all times, so when the handwheel of the NAFFCO NDR 098 is opened, water flows from the riser through the valve seat and out through the oblique outlet into the attached fire hose. The oblique outlet is angled downwards, which helps the hose hang naturally from the valve and reduces kinking at the connection.

The valve is a screw-down design: turning the handwheel raises or lowers a renewable disc against the seat inside the copper alloy body. NAFFCO states a water flow rate of 8.5 litres per second at 4 bar outlet pressure. As general background, BS 5041 Part 1 covers landing valves for wet risers, and the strap and padlock supplied with the valve allow the handwheel to be secured against unauthorised use while still being quickly released by the fire service.

Engineering Design of the NAFFCO NDR 098

The body, bonnet, female instantaneous outlet, blank cap and gland of the NAFFCO NDR 098 are copper alloy to EN 1982, while the stem is copper alloy to BS EN 12164. The handwheel is grey cast iron to BS EN 1561, painted black, and the body is painted red. The renewable disc facing, washer and gland seal are rubber to BS 1154, the bonnet seal is PTFE (Teflon), and the strap with padlock uses leather 12 mm wide and 2 mm thick with a non-ferrous lock.

Two maintenance details of the NAFFCO NDR 098 stand out on the datasheet. First, the disc facing rubber is of a replaceable type, so the sealing surface can be renewed without replacing the valve. Second, the gland seal can be replaced while the valve is under pressure with the valve fully closed, which avoids draining the riser for routine gland maintenance. The inlet flange is drilled to BS 4504 Part 2:1974 Table 16/21; the drawing for the NDR 098 shows a 165 mm flange with four 18 mm holes on a 125 mm PCD, and the NDR 100 shows a 185 mm flange with four 18 mm holes on a 145 mm PCD.

Key Features

NAFFCO lists the following features for the NAFFCO NDR 098 and NDR 100 oblique flanged landing valves.

• The NAFFCO NDR 098 is manufactured to comply with BS 5041 Part 1 for landing valves on wet risers.
• The delivery hose connection and blank cap comply with BS 336:2010.
• BSI Kitemark and LPCB certification is stated for the range, with the NDR 100 marked Kitemark approved.
• The body is copper alloy to EN 1982 and the handwheel is grey cast iron to BS EN 1561.
• The blank cap is copper alloy to EN 1982 and is retained by a chain.
• The gland seal can be replaced under pressure with the valve fully closed.
• The disc facing rubber is replaceable, extending service life.
• A strap and padlock secure the handwheel against unauthorised use; handwheel black, body red.

Industrial Applications

The NAFFCO NDR 098 is used at landing valve positions on wet riser systems in high-rise residential and office towers, hotels, hospitals, shopping centres, car parks and industrial buildings where the local civil defence authority requires firefighting water outlets on each floor. It is also used on hydrant main branches in warehouses and process plant buildings where a permanently charged system is installed. In Oman, fire protection designs for projects in Muscat, Sohar, Duqm and Salalah frequently reference BS 5041 landing valves and BS 336 instantaneous couplings, which are the standards stated on this datasheet.

Seven Star LLC supplies the NAFFCO NDR 098 and NDR 100 to fire protection contractors and maintenance companies throughout Oman and can advise on matching flange sizes to riser branches. Landing valves are typically part of a wider fire protection package that also includes grooved pipework joined with the Victaulic Style 107N QuickVic coupling, pressure boosting such as the Grundfos Hydro MPC booster set, and detection and alarm equipment such as the Gent Vigilon Plus fire alarm control panel.

Technical Specifications

NAFFCO NDR 098 data below is taken from the NAFFCO technical datasheet for oblique flanged-inlet landing valves.

Selection and Installation Notes

The notes in this section are general fire protection practice rather than NAFFCO instructions. Confirm whether the riser is wet or dry before selecting a landing valve, because BS 5041 Part 1 covers wet risers while dry risers are covered by a different part of the standard. Check the branch flange size and drilling against the BS 4504 Table 16/21 drilling shown on the datasheet, and choose between the DN50 NDR 098 and DN65 NDR 100 to suit the riser branch and the project specification.

Landing valves such as the NAFFCO NDR 098 are normally mounted inside a hose cabinet or riser cupboard at a height that allows firefighters to connect hoses easily, and the outlet orientation should be checked so that the hose can be run out without sharp bends. Final positions, heights and inspection requirements are set by the approved fire protection design and the local authority having jurisdiction, so always follow the project drawings.

How to Order

To request a quotation for the NAFFCO NDR 098 or NDR 100, send Seven Star LLC your required inlet size, quantity and project specification. Our team in Muscat can confirm availability and lead time, provide the NAFFCO technical datasheet available for download on this page, and support fire protection projects across Oman and the GCC.