1、 4100 N. FAIRFAX DR., SUITE 200 ARLINGTON, VIRGINIA 22203 2007 STANDARD for PERFORMANCE RATING OF THERMOSTATIC REFRIGERANT EXPANSION VALVES Standard 750 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted
2、 without license from IHS-,-,-IMPORTANT SAFETY DISCLAIMER ARI does not set safety standards and does not certify or guarantee the safety of any products, components or systems designed, tested, rated, installed or operated in accordance with this standard/guideline. It is strongly recommended that p
3、roducts be designed, constructed, assembled, installed and operated in accordance with nationally recognized safety standards and code requirements appropriate for products covered by this standard/guideline. ARI uses its best efforts to develop standards/guidelines employing state-of-the-art and ac
4、cepted industry practices. ARI does not certify or guarantee that any tests conducted under its standards/guidelines will be non-hazardous or free from risk. Note: This standard supersedes ARI Standard 750-2001. Price $10.00 (M) $20.00 (NM) Copyright 2007, by Air-Conditioning and Refrigeration Insti
5、tute Printed in U.S.A. Registered United States Patent and Trademark Office Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-TABLE OF CONTENTS SECTION PAGE Section 1. Purpo
6、se1 Section 2. Scope.1 Section 3. Definitions 1 Section 4. Test Requirements 2 Section 5. Rating Requirements.2 Section 6. Minimum Data Requirements for Published Ratings 3 Section 7. Marking and Nameplate Data 3 Section 8. Conformance Conditions .3 TABLES Table 1. Standard Rating Conditions 3 APPEN
7、DICES Appendix A. References - Normative 4 Appendix B. References - Informative.4 Appendix C. Recommended Maximum Operating Pressures for Pressure-Limiting Type Thermostatic Refrigerant Expansion Valves - Informative5 Appendix D. Recommended Color Coding for Valve Identification by Refrigerant - Inf
8、ormative 6 Appendix E. Recommended Standard Connection Sizes - Informative 7 TABLES FOR APPENDICES Table C1. Recommended Maximum Operating Pressures for Pressure-Limiting Type Thermostatic Refrigerant Expansion Valves 5 Table D1. Recommended Color Coding for Valve Identification by Refrigerant.6 Cop
9、yright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-Table E1a. Recommended Standard Connection Sizes - IP Nominal.7 Table E1b. Recommended Standard Connection Sizes - SI Nominal.
10、7 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 750-2007 1 PERFORMANCE RATING OF THERMOSTATIC REFRIGERANT EXPANSION VALVES Section 1. Purpose 1.1 Purpose. T
11、he purpose of this standard is to establish for Thermostatic Refrigerant Expansion Valves: definitions; test requirements; rating requirements; minimum data requirements for Published Ratings; marking and nameplate data; and conformance conditions. 1.1.1 Intent. This standard is intended for the gui
12、dance of the industry, including manufacturers, engineers, installers, contractors and users. 1.1.2 Review and Amendment. This standard is subject to review and amendment as technology advances. Section 2. Scope 2.1 Scope. This standard applies to Thermostatic Refrigerant Expansion Valves for use wi
13、th refrigerants listed in 2.1.1 at evaporator temperatures between 50F 10C and -40F -40C. 2.1.1 Refrigerants. The refrigerants included in this standard are: R-12, R-22, R-134a, R-404A, R-407C, R-410A, R-502 and R-507A. Section 3. Definitions All terms in this document follow the standard industry d
14、efinitions in the current edition of ASHRAE Terminology of Heating, Ventilation, Air Conditioning and Refrigeration unless otherwise defined in this section. 3.1 Capacity of Thermostatic Refrigerant Expansion Valves. The refrigerating effect produced by the evaporation of refrigerant which will pass
15、 through the valve under the following specified conditions: a. Liquid refrigerant temperature at the valve inlet b. Saturated evaporator temperature c. Pressure difference across the valve d. Static superheat set point e. Superheat change from the set point 3.2 Maximum Operating Pressure (MOP). The
16、 maximum equalizer (internal or external) pressure permitted by a pressure-limiting type Thermostatic Refrigerant Expansion Valve (See Appendix C). 3.3 Published Rating. A statement of the assigned values of those performance characteristics, under stated Rating Conditions, by which a unit may be ch
17、osen to fit its application. These values apply to all units of like nominal size and type (identification) produced by the same manufacturer. The term Published Rating includes the rating of all performance characteristics shown on the unit or published in specifications, advertising or other liter
18、ature controlled by the manufacturer, at stated Rating Conditions. 3.3.1 Application Rating. A rating based on tests performed at application Rating Conditions (other than Standard Rating Conditions). 3.3.2 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 3.4 Rating
19、Conditions. Any set of operating conditions under which a single level of performance results and which causes only that level of performance to occur. 3.4.1 Standard Rating Conditions. Rating conditions used as the basis of comparison for performance characteristics. Copyright Air-Conditioning and
20、Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 750-2007 2 3.5 “Shall“ or “Should“. “Shall“ or “should“ shall be interpreted as follows: 3.5.1 Shall. Where “shall“ or “shall not“ is used fo
21、r a provision specified, that provision is mandatory if compliance with the standard is claimed. 3.5.2 Should. “Should“ is used to indicate provisions which are not mandatory but which are desirable as good practice. 3.6 Thermostatic Refrigerant Expansion Valve. A controlling device which regulates
22、the flow of volatile refrigerant into an evaporator of a refrigeration system and which is actuated by changes in evaporator pressure and superheat of the refrigerant gas leaving the evaporator. 3.7 Thermostatic Refrigerant Expansion Valve Pressure Drop. The pressure drop across the valve, which is
23、the net pressure difference between the valve inlet and outlet. 3.8 Thermostatic Refrigerant Expansion Valve Superheat. The difference between the temperature of the thermal bulb and the dew point temperature corresponding to the refrigerant pressure at the valve outlet, or at the equalizer connecti
24、on, when provided. 3.8.1 Static Superheat. The superheat at which the manufacturer calibrates or “sets“ the thermostatic expansion valve. 3.9 Vapor-Free (Subcooled) Liquid Refrigerant. Refrigerant which has been cooled below the bubble point temperature for a given pressure. Section 4. Test Requirem
25、ents 4.1 Testing for Capacity. Thermostatic refrigerant expansion valve ratings shall be based on tests conducted in accordance with the test procedure outlined in ANSI/ASHRAE Standard 17. 4.1.1 Alternative flow test methods may be used provided the results obtained can be confirmed by the test meth
26、od specified in 4.1 within the tolerance specified in 5.5. Section 5. Rating Requirements 5.1 Published Capacity Ratings. Published capacity ratings shall consist of Standard Ratings and may include Application Ratings. Such ratings shall be based on tests of valves made for use with the refrigerant
27、 specified in the ratings. All Published Ratings shall be based on Vapor-free (Subcooled) Liquid Refrigerant entering the Thermostatic Refrigerant Expansion Valve. The tests shall be made in accordance with the test procedure outlined in Section 4 of this standard. 5.1.1 Standard Ratings. Standard R
28、atings of capacity shall be published for all Standard Rating Conditions, shown in Table 1, falling within the intended range of application of the valve. 5.1.2 Nominal Rating. The nominal rating is the equivalent capacity rating of the valve at the 40F 4C evaporator Standard Rating Condition (See S
29、tandard Rating Condition A in Table 1). 5.1.3 Application Ratings. Application Ratings provide capacities under operating conditions which differ from those in Table 1. Wherever Application Ratings are published or printed, they shall include a statement of conditions at which the ratings apply and
30、be accompanied by the pertinent Standard Rating(s) clearly designated as such. 5.2 Interpolation and Extrapolation of Air Test Data. Published capacity ratings shall be based on air-fixture tests made at two or more evaporator dew point temperatures. Air-fixture test data may be extrapolated or inte
31、rpolated no more than 15F 8C from test points and only when the same thermostatic charge is used. In the case of Refrigerants R-12 and R-134a, data may be extrapolated a maximum of 25F 14C below the lowest test point in order to obtain a rating at -40F -40C evaporator dew point temperature. 5.3 Supe
32、rheat Change. Every published capacity rating shall be based on the capacity resulting from a superheat change above the Static Superheat. This superheat change shall not exceed 7F 4C for any Published Rating unless clearly designated. Copyright Air-Conditioning and Refrigeration Institute Provided
33、by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 750-2007 3 5.4 Static Superheat. For purposes of rating, the Static Superheat shall be no less than 2F 1C. 5.5 Tolerance. To comply with this standard, published capacity rat
34、ings shall be based on data obtained in accordance with the provisions of this section, and shall be such that any production Thermostatic Refrigerant Expansion Valve selected at random and tested shall produce not less than 95% of its published rated capacity. Table 1. Standard Rating Conditions Li
35、quid Temperature (at expansion valve inlet) Saturated Condensing Temperature (at expansion valve inlet) Saturated Evaporating Temperature (at expansion valve outlet) Standard Rating Condition F C F C F C A 98 37 100 38 40 4.4 B 98 37 100 38 20 -6.7 C 98 37 100 38 -10 -23 D 98 37 100 38 -40 -40 Secti
36、on 6. Minimum Data Requirements for Published Ratings 6.1 Minimum Data Requirements for Published Ratings. As a minimum, Published Ratings shall include all Standard Ratings. All claims to ratings within the scope of this standard shall include the statement “Rated in accordance with ARI Standard 75
37、0“. All claims to ratings outside the scope of this standard shall include the statement “Outside the scope of ARI Standard 750”. Wherever Application Ratings are published or printed, they shall include a statement of the conditions at which the ratings apply. 6.2 Published Capacity Ratings. Capaci
38、ty ratings for net refrigerant capacity, Btu/h W or tons of refrigeration kW, shall be published along with at least the following pertinent operating conditions: a. Refrigerant designation(s) per ANSI/ASHRAE Standard 34 with Addenda b. Evaporator dew point temperature, F C c. Pressure drop across t
39、he valve, psi kPa d. Maximum superheat change from set point at which ratings apply, F C e. Capacity correction factors for liquid temperatures at the valve inlet which differ from the standard value of 98F 37C. (These include corrections for liquid density and refrigerating effect and are based on
40、an average evaporator temperature of 0.0F -18C). Section 7. Marking and Nameplate Data 7.1 Nameplate Data. Each Thermostatic Refrigerant Expansion Valve shall display the manufacturers name or trade name, model number, and refrigerant designation(s). Section 8. Conformance Conditions 8.1 Conformance
41、. While conformance with this standard is voluntary, conformance shall not be claimed or implied for products or equipment within the standards Purpose (Section 1) and Scope (Section 2) unless such product claims meet all of the requirements of the standard and all of the testing and rating requirem
42、ents are measured and reported in complete compliance with the standard. Any product that has not met all the requirements of the standard shall not reference, state, or acknowledge the standard in any written, oral, or electronic communication. Copyright Air-Conditioning and Refrigeration Institute
43、 Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 750-2007 4 APPENDIX A. REFERENCES - NORMATIVE A1 Listed here are all standards, handbooks and other publications essential to the formation and implementation of th
44、e standard. All references in this appendix are considered as part of the standard. A1.1 ANSI/ASHRAE Standard 17-1998 (RA 2003), Methods of Testing for Capacity Rating of Thermostatic Refrigerant Expansion Valves, 2003, American National Standards Institute/American Society of Heating, Refrigerating
45、 and Air-Conditioning Engineers, Inc., 25 West 43rdStreet, 4thFloor, New York, NY 10036, U.S.A./1791 Tullie Circle N.E., Atlanta, GA 30329, U.S.A. A1.2 ANSI/ASHRAE Standard 34-2004 with Addenda, Designation and Safety Classification of Refrigerants, 2004, American National Standards Institute/Americ
46、an Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 25 West 43rdStreet, 4thFloor, New York, NY 10036, U.S.A./1791 Tullie Circle N.E., Atlanta, GA 30329, U.S.A. A1.3 ASHRAE Terminology of Heating, Ventilation, Air Conditioning and Refrigeration, Second Edition, 1991, American S
47、ociety of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 1791 Tullie Circle N.E., Atlanta, GA 30329, U.S.A. APPENDIX B. REFERENCES - INFORMATIVE B1 Listed here are standards, handbooks and other publications which may provide useful information and background but are not considered ess
48、ential. References in this appendix are not considered part of the standard. B1.1 ARI Guideline N-2002, Assignment of Refrigerant Container Colors, 2002, Air-Conditioning and Refrigeration Institute, 4100 North Fairfax Drive, Suite 200, Arlington, VA 22203, U.S.A. Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 750-2007 5 APPENDIX C. RECOMMENDED MAXIMUM OPERATING PRESSURES FOR PRESSURE-LIMITING TYPE THERMOSTATIC REFRIGERANT EXPANSION V
