The pressure difference between the clean room and the adjacent room or the surrounding space is an important means to maintain indoor cleanliness or limit the spread of pollutants in the room. Commonly used clean room specifications for the pressure difference requirements.
"Good Manufacturing Practices (Revised in 2010)" (hereinafter referred to as Human GMP) provides:
The pressure difference between the clean area and the non-clean area and between the different clean areas should be no less than 10Pa. Appropriate differential pressure gradients should also be maintained between different functional areas (operating rooms) of the same cleanliness level, if necessary.
The revised Code for Design of Cleanrooms in the Pharmaceutical Industry, GB50457, is proposed to:
The static pressure difference between medical clean rooms of different air cleanliness levels and between medical clean rooms and non-clean rooms should not be less than 10 Pa, and the static pressure difference between medical clean room and outdoor atmosphere should not be less than 10 Pa.
In addition, the following medical clean rooms are required to maintain a relative negative pressure with the adjacent medical clean room:
1 a medical clean room that emits dust during the production process;
2 a medical clean room using organic solvents in the production process;
3 A medical clean room that produces a large amount of harmful substances, hot humid gas and odor during the production process;
4 Refining, drying, packaging room and packaging products of special products such as penicillin;
5 pathogen operating area;
6 Radiopharmaceutical production area.
"Clean Factory Design Code" GB50073-2013 provides:
The clean room (zone) and the surrounding space must maintain a certain pressure difference, and the positive pressure difference or negative pressure difference should be maintained according to the process requirements.
The pressure difference between different levels of clean room should not be less than 5Pa, the pressure difference between clean area and non-clean area should not be less than 5Pa, and the pressure difference between clean area and outdoor should not be less than 10Pa.
The "Code for the Quality Management of Veterinary Drug Production" promulgated in March 2002 (Order No. 11 of the Ministry of Agriculture) (referred to as veterinary drug GMP) provides:
The static pressure difference between adjacent clean rooms (zones) with different air cleanliness levels should be greater than 5 Pa. The static pressure difference between the clean room (zone) and the non-clean room (zone) should be greater than 10 Pa. The static pressure difference between the clean room (area) and the outdoor atmosphere (including the area directly communicating with the outdoor) should be greater than 12 Pa, and there should be a device indicating the differential pressure or a monitoring alarm system. For the clean room workshop of biological products, the absolute value of the static pressure difference specified above shall be determined according to the process requirements.
"Hospital Cleansing Department Building Technical Specifications" GB50333-2013 provides:
1 Between clean rooms with different cleanliness levels that are connected to each other, rooms with high cleanliness should maintain a relatively positive pressure for rooms with low cleanliness. The minimum static pressure difference should be greater than or equal to 5Pa, and the maximum static pressure difference should be less than 20Pa. The whistle should not be generated due to the pressure difference or the door opening should be affected.
2 Between the clean rooms of the same cleanliness level that are connected to each other, a suitable pressure difference should be maintained to maintain the required airflow direction.
3 Severely polluted rooms should be under negative pressure for adjacent rooms, and the minimum static pressure difference should be greater than or equal to 5Pa. The operating room used to control airborne infections should be a negative pressure operating room, and the negative pressure operating room should maintain a negative pressure difference of slightly below "0" on the technical interlayer of the ceiling.
4 The clean area should maintain a positive pressure on the non-clean area in contact with it, and the minimum static pressure difference should be greater than or equal to 5Pa.
"Technical Specifications for the Construction of Cleanrooms for Food Industry" GB50687-2011:
A static pressure difference of not less than 5 Pa shall be maintained between the clean rooms adjacent to the doors and windows and between the clean and non-clean areas, and the static pressure shall be maintained at a static pressure of not less than 10 Pa for the outdoor area. When the production process requires that the wall of the clean room be opened with an unobstructable opening, the flow direction of the hole and the average wind speed should be not less than 0.2 m/s.
Rooms with internal pollution should be kept at a relatively negative pressure, and rooms with control requirements for external pollution should maintain a relatively positive pressure.
"Biosafety Laboratory Building Technical Specifications" GB50346-2011 provides:
level
Minimum negative pressure relative to the atmosphere
Minimum negative pressure difference between the room and the adjacent room in the outdoor direction
Remarks
BSL-1/ABSL-1
——
——
Class A and B1 in BSL-2/ABSL-2
——
——
B2 in ABSL-2
-30
-10
The biological factors of operation are airborne and are not operated in a safety isolation device
Class A in BSL-3
-30
-10
The biological factor of operation is non-airborne
B1 in ABSL-3
-40
-15
Airborne but operated in a safety isolation device
Class A and B1 in ABSL-3
-60
-15
Operating non-airborne biological factors, or airborne but operating in a safety isolation device
B2 in ABSL-3
-80
-25
The biological factors of operation are airborne and are not operated in a safety isolation device
BSL-4
-60
-25
ABSL-4
-100
-25
The relative atmospheric pressure of the anatomical laboratory of the animal biosafety laboratory should be 10 Pa lower than that of the main laboratory.
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