API MPMS 7:2001 pdf download

API MPMS 7:2001 pdf download.Manual of Petroleum Measurement Standards Chapter 7一Temperature Determination.
On cargo tanks connected to the vessel’s inert gas system (IGS). the All’ should be designed and installed so that it can be maintained and caiibrated without dc-pressurizing the
IGS.
To permit accurate comparison between manual and automatic temperature measurement, the Al]’ deck penetration should be close (e.g.. preferably within I meter) to a location where manual gauging can be performed.
5.1.4.3.1 Location of Temperature Sensing Element(s)
The single-point (spot) and/or multiple-point temperature sensing elements should be installed close to a vapor lock valve, gauging hatch, or other suitable gauging access point. The following methods of installation are in general use:
a. Installed in a metal thermowell through the deck (lank roof). This vertical thermowell should allow for one or more (usually three) temperature sensing elements to be mounted from the deck, suspended by their individual metal cabling. down to various depths in the tank. When three temperature sensing elements are used, they should be located respectively in the upper third (approximately 70% to X0% of the tank hcight. in the middle (approximately 40% to 50% of the tank height) and in the lower third (approximately 15% to 20% of the tank height).
b. Installed as an integral pan of ATGs with level-sensing element(s) in contact with the liquid. The height of each temperature element may depend on the ATG mounting.
For both of the above methods, the ullage corresponding to the depth of each individual temperature sensing element for each tank should be readily available for the operator together with other ATG/A[T system data.
5.1.5 Thermowells for Fixed Electronic Temperature Elements
Thermowells for fixed electronic temperature elements should extend through the tank shell for at least 900 millimeters (36 inches) to reduce errors due to temperature ditTerences between the liquid in the tank and the anihient conditions. The thcnnowcll material should be compatible with the liquid product. Usually Type 304 or 316 stainless steel is specified.
The thcrmowclls should be located near the ladder or stairway to facilitate maintenance and located as far as possible from the heating coils and the tank inlet and outlet.
Thermowells extending through the tank shell cannot be used on floating-roof or pan-roof tanks above the minimum roof height. Various vertical proprietary thermowells are available to support averaging temperature elements in floating- roof or pan-roof tanks.
5.1.6 Telemetry and Readout Equipment
Refer to 5.6 of this standard. Additional information may be found in API MPMS Chapter 21.
5.2，PORTABLE ELECTRONIC THERMOMETERS (PETs)
Portable electronic thermometers used for custody transfer shall meet the accuracy requirements of Table 3 and shall come to equilibrium within the immersion time requirements of Table 6.