86.310-79—Sampling and analytical system; component specifications.
(i)
In the HC sample path must be maintained above 110 °C (230 °F) and shall not exceed 230 °C (446 °F).
(ii)
In the NOX sample path must be maintained above 60 °C (140 °F) and shall not exceed 230 °C (446 °F).
(i)
In the HC sample path must be maintained above 180 °C (356 °F) and shall not exceed 230 °C (446 °F).
(ii)
In the NOX sample path must be maintained above 60 °C (140 °F) and shall not exceed 230 °C (446 °F).
Code of Federal Regulations
Code of Federal Regulations
636
(3)
The sample line outside wall temperature must be maintained at the temperature specified in this paragraph. An exception is made for the first 4 feet of sample line from the exhaust duct. The upper temperature tolerance for this 4 foot section is waived and only the minimum temperature specification applies.
(b) Sample probe.
(1)
The sample probe shall be a straight, closed end, stainless steel, multi-hole probe. The Inside Diameter (I.D.) shall not be greater than the I.D. of the sample line (=.010 in.). The wall thickness of the probe shall not be greater than .040 inch. The fitting that attaches the probe to the exhaust pipe shall be as small as practical in order to minimize heat loss from the probe.
(2)
There shall be a minimum of three holes in the probe. The spacing of the radial planes for each hole in the probe must be such that they cover approximately equal cross-sectional areas of the exhaust duct. The angular spacing of the holes must be approximately equal. The angular spacing of any two holes in one plane may not be 180° ±20° (i.e., section C-C of Figure D79-2). The holes should be sized such that each has approximately the same flow. If only three holes are used, they may not all be in the same radial plane. See Figure D79-2.
(3)
The probe shall extend radially across the exhaust duct. The probe must pass through the approximate center and must extend across at least 80 percent of the diameter of the duct.
(2)
If valve V2 is used, the sample probe must connect directly to valve V2. The location of optional valve V2 may not be greater than 4 feet from the exhaust duct.
(3)
The location of optional valve V16 may not be greater than 24 inches from the sample pump. The leakage rate for this section on the pressure side of the sample pump may not exceed the leakage rate specification for the vacuum side of the pump.
(d) Venting.
All vents including analyzer vents, bypass flow, and pressure relief vents of regulators should be vented in such a manner to avoid endangering personnel in the immediate area.