[Code of Federal Regulations]
[Title 40, Volume 31]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1065.130]

[Page 688-690]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 1065_ENGINE-TESTING PROCEDURES--Table of Contents
 
                   Subpart B_Equipment Specifications
 
Sec.  1065.130  Engine exhaust.

    (a) General. Use the exhaust system installed with the engine or one 
that represents a typical in-use configuration. This includes any 
applicable aftertreatment devices.
    (b) Aftertreatment configuration. If you do not use the exhaust 
system installed with the engine, configure any aftertreatment devices 
as follows:
    (1) Position any aftertreatment device so its distance from the 
nearest exhaust manifold flange or turbocharger outlet is within the 
range specified by the engine manufacturer in the application for 
certification. If this distance is not specified, position 
aftertreatment devices to represent typical in-use vehicle 
configurations.

[[Page 689]]

    (2) You may use laboratory exhaust tubing upstream of any 
aftertreatment device that is of diameter(s) typical of in-use 
configurations. If you use laboratory exhaust tubing upstream of any 
aftertreatment device, position each aftertreatment device according to 
paragraph (b)(1) of this section.
    (c) Sampling system connections. Connect an engine's exhaust system 
to any raw sampling location or dilution stage, as follows:
    (1) Minimize laboratory exhaust tubing lengths and use a total 
length of laboratory tubing of no more than 10 m or 50 outside 
diameters, whichever is greater. If laboratory exhaust tubing consists 
of several different outside tubing diameters, count the number of 
diameters of length of each individual diameter, then sum all the 
diameters to determine the total length of exhaust tubing in diameters. 
Use the mean outside diameter of any converging or diverging sections of 
tubing. Use outside hydraulic diameters of any noncircular sections.
    (2) You may install short sections of flexible laboratory exhaust 
tubing at any location in the engine or laboratory exhaust systems. You 
may use up to a combined total of 2 m or 10 outside diameters of 
flexible exhaust tubing.
    (3) Insulate any laboratory exhaust tubing downstream of the first 
25 outside diameters of length.
    (4) Use laboratory exhaust tubing materials that are smooth-walled, 
electrically conductive, and not reactive with exhaust constituents. 
Stainless steel is an acceptable material.
    (5) We recommend that you use laboratory exhaust tubing that has 
either a wall thickness of less than 2 mm or is air gap-insulated to 
minimize temperature differences between the wall and the exhaust.
    (d) In-line instruments. You may insert instruments into the 
laboratory exhaust tubing, such as an in-line smoke meter. If you do 
this, you may leave a length of up to 5 outside diameters of laboratory 
exhaust tubing uninsulated on each side of each instrument, but you must 
leave a length of no more than 25 outside diameters of laboratory 
exhaust tubing uninsulated in total, including any lengths adjacent to 
in-line instruments.
    (e) Grounding. Electrically ground the entire exhaust system.
    (f) Forced cooldown. You may install a forced cooldown system for an 
exhaust aftertreatment device according to Sec.  1065.530(a)(1)(i).
    (g) Exhaust restriction. Use an exhaust restriction that represents 
the performance of production engines. Make sure the exhaust restriction 
set point is either (80 to 100) % of the maximum exhaust restriction 
specified by the manufacturer; or if the maximum is 5 kPa or less, make 
sure the set point is no less than 1.0 kPa from the maximum. For 
example, if the maximum back pressure is 4.5 kPa, do not use an exhaust 
restriction set point that is less than 3.5 kPa. Measure and set this 
pressure at the location and at the speed, torque and aftertreatment set 
points specified by the manufacturer. As the manufacturer, you are 
liable for emission compliance for all values up to the maximum 
restriction you specify for a particular engine.
    (h) Open crankcase emissions. If the standard-setting part requires 
measuring open crankcase emissions, you may either measure open 
crankcase emissions separately using a method that we approve in 
advance, or route open crankcase emissions directly into the exhaust 
system for emission measurement as follows:
    (1) Use laboratory tubing materials that are smooth-walled, 
electrically conductive, and not reactive with crankcase emissions. 
Stainless steel is an acceptable material.
    Minimize tube lengths. We also recommend using heated or thin-walled 
or air gap-insulated tubing to minimize temperature differences between 
the wall and the crankcase emission constituents.
    (2) Minimize the number of bends in the laboratory crankcase tubing 
and maximize the radius of any unavoidable bend.
    (3) Use laboratory crankcase exhaust tubing that meets the engine 
manufacturer's specifications for crankcase back pressure.
    (4) Connect the crankcase exhaust tubing into the raw exhaust 
downstream of any aftertreatment system, downstream of any installed 
exhaust restriction, and sufficiently upstream

[[Page 690]]

of any sample probes to ensure complete mixing with the engine's exhaust 
before sampling. Extend the crankcase exhaust tube into the free stream 
of exhaust to avoid boundary-layer effects and to promote mixing. You 
may orient the crankcase exhaust tube's outlet in any direction relative 
to the raw exhaust flow.