306 Positive displacement meter
“In-line examination of all parts exposed to the process liquid is simple. First depressurize the meter. Then by unscrewing six cap screws and removing the meter cover, the rotor can be slipped off for inspection or replacement. The process liquid enters the metering chamber through the inlet connection. As the liquid follows the 360 degree loop, it is separated into two equal streams. These two streams are forced into a series of vortices in the body and cover inserts and cause the rotor to rotate in proportion to the rate of flow. Rotation of the rotor is transmitted through the shaft and gears to the register assembly, where the liquid flow is indicated.
The rotor, which is the measuring element of the flow meter, is constructed of 316 stainless steel and has chrome-plated shaft ends for bearing surfaces. The standard rotor hub is made of non-clad 316 stainless steel for superior corrosion resistance. An optional rotor hub is clad with a Viton or Buna-N elastomer for improved flow at very low flow rates. The spring-loaded blades are made of a stainless steel substrate with a Buna-N, Viton, or Teflon covering.
The Flotrac meter body is constructed of SA-216 WCB epoxycoated cast steel with an SA-105 forged steel cover. The impeller and housing inserts are made of glass-filled Ryton®, which is practically impervious to dissolved salts and alkalis, water, most acids, and low-viscosity hydrocarbon liquids. Other wetted parts include 300 series stainless steel and a Buna-N body seal O-ring. The assembly is suitable for sour non-NACE service when the non-wetted body bolts are supplied as optional grade L7M and the body O-ring is supplied in Viton. The rotor bearings and journals are made of special materials that provide exceptional service life with water or non-lubricating liquids. The register assembly features a sealed weatherproof aluminum case. The meter is compliant with ASME B31.1 and B31.3 requirements.”