This is a gravity feed application and we are working with limited head so we cannot raise the flowmeter. We may be able to lower the slab it is supported on to effectively raise it though. Looks like we may have to.
Since the electronics (conductors used to generate the electromagnetic field) are essentially hermetically sealed indide the pipe, couldn't 501.15 B 2 Exeption No. 1 apply?
Exception No. 1: Metal conduit that contains no unions, couplings, boxes, or fittings, and passes completely through a Class I, Division 2 location with no fittings less than 300 mm (12 in.) beyond each boundary, shall not be required to be sealed if the termination points of the unbroken conduit are in unclassified locations.
I realize this isn't conduit, but the application is essentially the same.
The flowmeter does have an "Ex" Zone 2 rating, which I understand is not acceptable (see
http://forums.mikeholt.com/showthread.php?t=103285) but how does 500.8 A apply?
500.8
Articles 500 through 504 require equipment construction and installation that ensure safe performance under conditions of proper use and maintenance.
FPN No. 1: It is important that inspection authorities and users exercise more than ordinary care with regard to installation and maintenance.
FPN No. 2: Since there is no consistent relationship between explosion properties and ignition temperature, the two are independent requirements.
FPN No. 3: Low ambient conditions require special consideration. Explosionproof or dust-ignitionproof equipment may not be suitable for use at temperatures lower than -25?C (-13?F) unless they are identified for low-temperature service. However, at low ambient temperatures, flammable concentrations of vapors may not exist in a location classified as Class I, Division 1 at normal ambient temperature.
(A) Suitability. Suitability of identified equipment shall be determined by one of the following:
(1) Equipment listing or labeling
(2) Evidence of equipment evaluation from a qualified testing laboratory or inspection agency concerned with product evaluation
(3) Evidence acceptable to the authority having jurisdiction such as a manufacturer's self-evaluation or an owner's engineering judgment.
FPN: Additional documentation for equipment may include certificates demonstrating compliance with applicable equipment standards, indicating special conditions of use, and other pertinent information.
Lowering the slab seems to be the answer by getting it out of the hazardous area altogether, but I am curious to see how the other areas of the code apply, or don't.