SOA - Orifice Assembly

Transcription

1 SOA - Orifice Assembly March 2013 SOA Features Available to suit pipe sizes up to 150 NB Simple and quick removal of orifice plates Stainless steel orifice plates as standard Wide range of plate sizes to EN5167 Screwed and weldable flanges available Robust design Optional plate size Suitable for temperatures up to 350 C FNAC Metering Orifice Assemblies provide accurate measurement of flows of gas or air to industrial burners and combustion systems. The assembly consists of specially designed cast iron or standard PN10 steel flanges with provision for pressure sampling, in between which is held an easily removable, stainless steel orifice plates. Pressure test points are fitted as standard on all orifice meter assemblies. FNAC can provide the orifice plate blank for customer boring or pre-bored from a range of standard sizes. Plates bored to special customer requirements are also available. The FNAC Metering Orifice Assemblies are available in two versions: screwed (SSOA) or weldable flanges (SWOA). All standard plate sizes are based on a differential pressure drop of 10mbar. NOTE: due to the requirements of current European and UK codes of practice, BS EN 746-2:2010, screwed meters larger than 2 bsp can only be used to measure air flow. Above this size, all gas meters must have weldable flanges. Design Considerations Under standard conditions, the maximum inlet pressure to the SOA should not exceed 1bar. Higher pressures are possible with the use of special sealing materials refer to FNAC. Installation It is important to install the SOA unit in a straight section of pipework. The minimum length of straight section required is dependant upon the location but even under the most favourable circumstances 10 D upstream and 5 D downstream is required (where D = the inside pipe diameter). The exact requirements are dependant upon the nature of the up-stream and downstream fittings, (i.e. valves, bends) and the diameter ratio of the orifice plate. As a general rule, the more bends before an SOA and the larger the diameter ratio, then the longer the upstream straight section must be. Some installations may require as much as 80 D upstream of the SOA. For further information consult either EN ISO :1997 or contact FNAC. Ordering Information When placing your order, please confirm the Part Code you require (ref. Table 1) and the desired plate size. Should you require a plate size that is not listed, please contact FNAC with the following information: a) Required SOA size/pipe size b) Medium with density at NTP c) Upstream temperature of Medium ( C) d) Required Differential Pressure Drop P (mbar) e) Upstream Supply Pressure (prior to SOA) d) Required Flow of Medium (Nm 3 /h) Maintenance / Spares Under normal circumstances, the SOA will require no maintenance. There are no spares for this item. Heath Mill Road, Wolverhampton WV5 8BD England Tel +44 (0) Fax +44 (0) fna.salesuk@fivesgroup.com

2 Page 2 Plate Selection (Medium - Air) Air Flow SWOA - 50 SWOA - 65 SWOA - 80 SWOA SWOA Nm 3 /h SSOA - 50 SSOA - 65 SSOA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A Plate Selection (Medium - Natural Gas) Gas Flow SWOA - 10 SWOA - 15 SWOA - 20 SWOA - 25 SWOA - 32 Nm 3 /h SSOA - 10 SSOA - 15 SSOA - 20 SSOA - 25 SSOA G G G G G G G G G G G G G G G G G G G G Gas Flow SWOA - 40 SWOA - 50 SWOA - 65 SWOA - 80 SWOA Nm 3 /h SSOA - 40 SSOA - 50 SSOA - 65 SSOA - 80 SSOA G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G

3 Page 3 Flow Characteristics Air Flow - Combustion air (Nm 3 /h) (reference conditions - S.G 1.0, pressure 60 mbar, temperature 20 C) 10,000 1, Pressure drop across orifice (mbar) A1250 A800 A600 A450 A350 A250 A200 A150 A100 A70 A50 A35 A25 A20 A15 A10 Flow Characteristics Gas Flow - Natural gas (Nm 3 /h) (reference conditions - S.G 0.56, pressure 40 mbar, temperature 20 C) 10,000 1, Pressure drop across orifice (mbar) G700 G500 G400 G300 G200 G150 G100 G70 G50 G35 G25 G20 G15 G10 G2 G6

4 Page 4 Dimensions Table 1

5 Page 5 Dimensions Table 2 Dimensions Table 3 WARNING: The data outlined is for information only and does not form part of any contract. Our policy is one of continuous improvement and we therefore reserve the right to modify specifications or dimensions without prior warning. Situations dangerous to personnel and property can develop from incorrect installation and operation of combustion equipment. Fives North American Combustion UK, Ltd urges compliance with International, National and Local Safety Standards and that installation is carried out by properly qualified personnel.