SOP on Control of Sieves and Screens

  • Objective:To lay down a procedure for Control of Sieves and Screens of different Equipments.
  • Scope:This Standard Operating Procedure is applicable for formulation plant of pharmaceutical company name with location.
  • Responsibility
    • Production Supervisor / Officer shall be responsible for implementation of the procedure as per this SOP.
    • Head-Production / designee shall be responsible for compliance of this SOP.
  • Abbreviations and Definitions

SS :Stainless Steel

BIS :Bureau of Indian Standard

BSS :British Standard Sieve

ISO :International Organization for Standardization

SOP:Standard Operating Procedure

QA :Quality Assurance

MM :Material Management

  • Procedure
      • Sieves and Screens shall be indent as per required sieve number and screen size.
      • Indent shall be raised by Production Supervisor / Officer.
      • Indent for the sieves and screens shall be made as per coding specification.
      • Indent shall be approved by Head-Production/designee and submit to MM department.
      • MM department shall send the purchase order to the manufacturer.
      • Number of Sieves and Screens received, shall be checked as per Purchase Order.
      • Sieves and Screens Coding shall be checked as per Purchase Order.
      • Integrity of Sieves and Screens shall be checked by Nominal Aperture Calibrator with Magnification.
      • For the mesh size less then 40 the calibrator shall be placed on the wire mesh and the individuals Opening is visualized by using the fine tunings.
      • The distance between adjacent parallel wire (Nominal Aperture) is measured in both wrap and weft direction.
      • Ten such readings shall be taken all over the mesh
      • The average of these readings shall be the nominal aperture of the wire mesh.
      • The nominal aperture size shall be compared with the standard size specified in Annexure-3 and Annexure-4 and if it falls within the specified tolerance the sieve is accepted.
      • For the mesh size 40-200. The calibrator shall be placed on the wire mesh and count the number of wires in 2.5 mm.
      • Multiply the counted number of wires with 10 it gives the number of wires in a linear inch, i.e. 25.4mm.
      • The wire diameter of a particular mesh shall be taken from Annexure-7.
      • The nominal aperture size of the wire mesh shall be calculated by using the formula given below.

D = Diameter of wire

N = Mesh count = Number of wires/linear inch

Nominal Aperture size = (25.4/N)-D.

  • All the screens and sieves shall be of SS 316 material of construction with lead free welding (e.g. argon arc welding) and shall comply with BIS / ISO / BSS or Pharmacopoeial standard.
  • On receiving new sieve / screen entry shall be made in Change Parts Register as per Annexure-1.
  • Each sieve shall be coded with Identification Number either engraved / written on its SS parts or silicon part, or shall be labelled (written) under the transparent silicon or Teflon ring.
  • For numbering of the sieve or screen, first two letters shall represent the type of equipment then a ‘dash’ then size of the mesh in three digits again ‘dash’ and finally serial number in three digits.
  • The identification number for the sieves or screen of the equipment shall be as following:

Fisrt 2 digits shall denote name of the equipment like MS for Machenical Sifter

Third digit shall denote dash (-)

Fourth, fifth and Sixth digit shall denote mesh size e.g. For mesh size 5 shall be written as 005

Seventh digit shall denote dash (-)

Eight, ninth and tenth digit shall denote serial number of the sieve / screen.

  • Machenical Sifter / Sifter: The numbering shall start with abbreviation of MS as equipment name, then sieve size in number (in the case of wire mesh) and finally serial number of the sieve e.g.

Sieve with sieve size of 8 mesh shall be numbered as

MS-008-001, MS-008-002 etc.

Sieve with sieve size of 100 meshes shall be numbered as

MS-100-001, MS-100-002 etc.

  • Each sieve / screen shall be certified by its manufacturer for its material of construction, sieve no., and sieve size.
  • Record of the sieves / screen and their identification numbers shall be maintained in Change Parts Register (Annexure-1)
  • In case any damage is observed during inspection prior to use , the same sieve / screen shall be immediately discarded by marking ‘Rejected’ with a permanent marker on its ring duly signed by Production Supervisor / Officer with date. Rejected sieve / screen shall be sending to Engineering Department for disposal after affixing the label ‘SCRAP ITEM’ duly filled and singned by Production Supervisor / Officer.
  • After use sieve / screen shall be cleaned along with its parent equipment considering it a part of parent equipment comply its SOP and after cleaning cover with the stretch wraps and keep in the sieve storage area.
  • Sieve / Screen Status Register shall be maintained as per Annexure-2.
  • Forms and Records
    • Sieves / Screen Inventory Register -Annexure-I
    • Sieves / Screen Status Register -Annexure-II
    • Tolerance on Aperture Width -Annexure-III
    • Sieve/Screen Inspection record -Annexure-IV
    • Standard Wire Diameter and Permissible Variations -Annexure-V
  • Distribution
    • Master Copy – Documentation Cell (QA)
    • Controlled Copies – Production, Quality Assurance,   Administration and Engineering.
  • History
Revision NumberReason for revision
        –00New SOP


                                          Sieves / Screen Inventory Register

DateSupplier NameBill No. or Invoice No. with dateItem descriptionQuantityMother Equipment Name & ID NumberAssigned Identification NumberRemarks OK / Not OKSignature & Date


                                        SIEVES / SCREENS STATUS REGISTER

Mother Equipment Name: ……………………………

Mother Equipment Identification Number: ……………                   Date …………………

S. No.DescriptionIdentification NumberTotal quantity Checked ByTotal rejected quantity in numbersQuantity Left in NumbersSent for disposal (date)Sent for disposal (By)


                                              Tolerance on Aperture Width

Nominal Aperture Width In MicrometersTolerances Of Average Aperture In Percentage
I000 to 500 microns+ / – 5%
400 to 200 microns+ / – 6%
I60 to 100 microns+ / – 7%
80 microns+ / – 8%
63 microns+ / – 9%
50 microns+ / -10%
40 microns+ / – 11%
32 microns+ / – 13%
25 microns+ / – 15%
20 microns+ / – 17%


   Annexure- IV

                      Standard Wire Diameter and Permissible Variations    

Sieve SizeMeshWire Diameter In MicronsTolerance on Wire Diameters
4.75 mm41016-15 % to +30 %
3.35 mm6914-15 % to +30 %
2.80 mm7813-15 % to +30 %
2.36 mm8711-15 % to +30 %
2.00 mm10508-15 % to +30 %
1.70 mm12416-15 % to +30 %
1.40 mm14416-15 % to +30 %
1.18 mm16375-15 % to +30 %
1.00 mm18375-15 % to +30 %
850 microns20416-15 % to +30 %
710 microns24345-15 % to +30 %
600 microns30254-15 % to +30 %
500 microns36193-15 % to +30 %
425 microns40213-15 % to +30 %
355 microns44233-15 % to +30 %
300 microns50193-15 % to +35 %
250 microns60172-15 % to +35 %
212 microns70152-15 % to +35 %
180 microns80132-15 % to +35 %
150 microns100101-15 % to +35 %
125 microns12081-15 % to +35 %
106 microns15061-15 % to +35 %
90 microns17061-15 % to +35 %
75 microns20050-15 % to +35 %

                                                    Annexure -V 

                                    Sieve/ Screen Inspection Record

Date___________________                 Sieve / Screen Size No________________

Supplier Name___________                 Received By_________________________    


Size of Sieve/Screen.                                                         LocationAv .Size


Inspected By /Date   —————–


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About Pharmaceutical Guidanace

Mr. Shiv Kumar is the Author and founder of pharmaceutical guidance, he is a pharmaceutical Professional from India having more than 14 years of rich experience in pharmaceutical field. During his career, he work in quality assurance department with multinational company’s i.e Zydus Cadila Ltd, Unichem Laboratories Ltd, Indoco remedies Ltd, Panacea Biotec Ltd, Nectar life Science Ltd. During his experience, he face may regulatory Audit i.e. USFDA, MHRA, ANVISA, MCC, TGA, EU –GMP, WHO –Geneva, ISO 9001-2008 and many ROW Regularities Audit i.e.Uganda,Kenya, Tanzania, Zimbabwe. He is currently leading a regulatory pharmaceutical company as a head Quality. You can join him by Email, Facebook, Google+, Twitter and YouTube

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