CEN/TC 197/WG 3

Date: 2024-12-18

prEN 18183:2025

Secretariat:

Pumps — Specification for Gland Packings manufactured from Yarns and Ribbons

Pumpen — Spezifikation für Stopfbuchspackungen gefertigt aus Garnen und Bändern

Pompes — Spécifications pour les garnitures de presse-étoupe fabriquées à partir de fils et de rubans

Contents Page

European foreword 3

Introduction 4

1 Scope 5

2 Normative references 5

3 Terms and definitions 5

4 Packing types 5

4.1 Description 5

4.2 Coding system 7

4.3 Coding system example 8

4.4 Elastomeric cored packings 8

5 Packing construction 8

6 Shape and cross-section 8

7 Size 8

8 Physical quality 9

9 Packaging 9

10 Marking 9

11 Quality of materials 9

11.1 Yarns 9

11.1.1 Tensile Strength and Elongation at Break 9

11.1.2 Shrinkage 10

11.2 Packings 11

11.2.1 Creep Resistance 11

11.2.2 PTFE Packings (Group 5) 12

11.2.3 Expanded Graphite Packings (Group 6D) 12

Annex A (normative) Methods of test 13

Annex B (normative) Information to be supplied by the purchaser 16

Bibliography 17

European foreword

This document (prEN 18183:2025) has been prepared by Technical Committee CEN/TC 197 “Pumps”, the secretariat of which is held by AFNOR.

This document is currently submitted to the CEN Enquiry.

Introduction

This document was originally drafted by a joint Technical Task Force of the Packings Division of the European Sealing Association (ESA) and the Compression Packing Division of the Fluid Sealing Association and is approved by both organisations as a suitable reference for the packing types described.

Certain of the packings contain polytetrafluoroethylene (PTFE) which, when heated to elevated temperatures, can produce fumes which give unpleasant effects if inhaled. Care should be taken to avoid contamination of tobacco products with PTFE.

This document provides a method of describing the materials, impregnates and lubricants for various types of yarn and ribbon based packings intended for use as gland seals in mechanical equipment such as pumps, mixers, etc. It does not include similar products intended for other duties such as thermal insulation.

Guidance is also given regarding dimensional and physical quality aspects of the packings and requirements for packaging and marking.

Tests are specified for the determination of lubricant content, size and mass.

NOTE 1 The information supplied by the purchaser at the time of enquiry and/or order is given in Annex B.

NOTE 2 All packings are free from introduced asbestos fibres in conformance with Annex XVII of REACH.

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 18067, Textiles — Synthetic filament yarns — Determination of shrinkage in dry-hot air (after treatment)

FSA/ESA, Publication ‘Compression Packings Technical Manual - 4th Edition

For the purposes of this document, the terms and definitions given in the Glossary of Terms in the FSA/ESA Compression Packing Technical Manual 4th Edition, 2018, apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp/

— IEC Electropedia: available at https://www.electropedia.org/

Each packing shall be described by a unique series of codes which define the following attributes:

1. The generic yarn Group or Groups,

2. The specific yarns within the Group,

3. The minimum weight of each yarn as a percentage of the total weight of the packing,

4. The minimum total weight of yarns as a percentage of the total weight of the packing,

5. The type of impregnation (where used),

6. The amount of impregnant percentage by weight,

7. The type of lubricating oil or grease (where used),

8. The amount of lubricant percentage by weight,

9. The type of reinforcement (where used),

10. The allowable density range in g/cm3,

11. Whether the packing has an elastomeric core.

Table 1 indicates the packing types.

Table 1 — Packing types

Table 2 indicates the impregnant and lubricant types.

Table 2 — Impregnant and Lubricant Types

Table 3 indicates the reinforcement types.

Table 3 — Reinforcement Types

Each packing description shall consist of a sequence of codes separated by semi-colons as follows:

1. Yarn group, yarn code as shown in Table 1, (e.g. 5A),

2. Minimum total yarn content by weight %.

Where more than one yarn is present the details for each yarn should be followed by its percentage by weight of the total packing and the details for each yarn shall be separated by a point sign
(e.g. 5C50.4A40),

3. Impregnant type as indicated in Table 2 and minimum % by weight (e.g. P10),

4. Lubricant type as indicated in Table 2 and minimum % by weight when determined by the method specified in A.1 (e.g. S15),

5. Reinforcement type as indicated in Table 3 (e.g. Gl),

6. Density range of finished packing when determined by the method specified in A.3
(e.g. 1.6/1.9 g/cm³).

Where the yarn and/or lubricant content of the packing varies depending on the cross-section size, the values quoted should be for the size for which these values are lowest.

A packing coded ‘5C50.4A40;P10;X;Y;1.6/1.9’ describes a packing manufactured from a combination of 50 % ePTFE/graphite and 40 % Para –Aramid yarns (i.e. a minimum total yarn content of 90 %) impregnated with a minimum of 10 % PTFE impregnation and no additional lubricant or reinforcement having a finished density between 1.6 and 1.9 g.cm-1.

Packings of any of the types can also be manufactured with an elastomeric core of circular, square or rectangular cross-section.

The cross-sectional area of such cores shall not exceed 50% of the packing cross-sectional area.

Where the packing contains an elastomeric core the packing code shall be as specified in 4.2 with the addition of the letter E (e.g. 5C;70;P10;X;Y;1.6/1.9;E).

All packing types except those in expanded graphite and glass or ceramic shall be manufactured using the minimum number of tracks indicated in Table 4.

Table 4 — Construction

The packing shall be provided in length form unless requested as dye-formed or cut rings.

The packing shall have a nominal square cross-section unless otherwise specified.

The cross-section size of the packing when determined in accordance with the procedure described in A.2 shall not vary from the nominal cross-section size in either direction by more than the limits given in Table 5.

Table 5 — Cross-section tolerances

All packing shall be of dense, firm yet flexible construction and shall have a regular surface displaying no obvious interstices or faults. The cross-section shape shall be reasonably uniform throughout the length.

In the case of square section, the packing shall have well defined corners and the firmness shall be evident both between faces and across corners.

Packings shall display no twisted or badly joined yarns.

There shall be no significant colour variation of any given packing; in particular there shall be no obvious dark patches in a light coloured packing.

All gland packings shall be despatched coiled in sealed parcels with no stress and be protected against damage and ingress of dirt in transit and storage.

NOTE Packings intended for use with food, potable water or for oxygen service can have additional cleanliness requirements in accordance with local standards or regulations.

Each parcel shall be clearly and legibly marked with the following information:

a) the manufacturer’s name or other means of identification,

b) the number of this document followed by the Packing Code (e.g. ESA PD002/ 5C;70;P10;X;Y;1.6/1.9;E),

c) the cross-section size and either the length or weight of the gland packing,

d) the month and year of manufacture.

Where relevant, warning labels and safety instructions as required by any relevant legislation shall be included.

The packings shall be stored in suitable conditions to prevent degradation. Manufacturers can supply storage recommendations upon request.

Marking ESA PD 002 on or in relation to a product represents a manufacturer’s declaration of conformity and that the product meets the requirements of this document.

When tested in accordance with Annex A, the tensile strength and elongation at break of the packing yarns shall be in accordance with Table 6.

Table 6 — Tensile Strength and Elongation at Break of Packing Yarns
(Nominal tex > 200)

When tested in accordance with Annex A at the temperatures indicated, the shrinkage of the packing yarns shall be in accordance with Table 7.

Table 7 — Shrinkage of Packing Yarns

Packing types, when tested at room temperature in accordance with A.6, shall exhibit resistance to creep in accordance with Table 8.

Table 8 — Creep Resistance of Packings

When heated at 250°C for 2 hours by the method specified in A.1 the weight loss shall be not greater than 5% of the original weight.

All packings containing PTFE yarn or PTFE dispersion should be free from added PFOA (perfluorooctanoic acid) or PFOS (Perfluorooctane sulfonic acid) or their salts and derivatives and any residues of these compounds should be in accordance with Annex XVII of REACH.

When tested by the method specified in ASTM 5373 the graphite content shall be equal or greater than 98%.

When heated at 670°C for 1 hour by the method specified in ASTM C561 the weight loss shall be not greater than 4%.

When determined by the method specified in ASTM D4239 the sulphur content shall be not greater than 300 ppm.

When determined by the method specified in ASTM D4327 the chloride content shall be not greater than 25 ppm.

When determined by the method specified in ASTM D4327 the fluoride content shall be not greater than 10 ppm.

1. 
   (normative)
   
   Methods of test
   1. Determination of grease, oil or binder content
      1. Principle

The lubricant content shall be determined by the loss in mass of a sample after extraction with a solvent and subsequent evaporation of the solvent. Solid lubricants shall be physically removed from the sample after being subjected to the extraction process.

• • 1. Reagent

Petroleum spirit (boiling range 40 °C to 60 °C), of general laboratory reagent quality shall be used.

WARNING. Petroleum spirit is highly flammable. Take precautions to avoid ignition. Also avoid breathing the vapour and contact of the petroleum spirit with skin or eyes.

• • 1. Apparatus

— Soxhlet extractor, as specified in BS 2071 with a nominal capacity of 100 ml, with a socket joint of 34/35 size, as specified in BS 572, the cone joint of 24/29 size, as specified in BS 572 and the extraction thimble fitted with a fritted glass plate as specified in ISO 4793 with a maximum pore diameter within the range 100 μm to 160 μm should be used.

NOTE Suitable sizes of extraction thimble and condenser are given in BS 2071, Annex A.

— Condenser

— Boiling flask, with conical ground glass joint, size 29/32 as specified in EN ISO 4797

— Air circulation oven, capable of being maintained at a temperature of 107.5 ± 2.5 °C.

— Balance, of sufficient capacity to weigh the extraction thimble to an accuracy of 0.1 mg.

— Desiccator

— Weighing bottle

— Evaporating dish

— Silica or platinum crucible

— Muffle furnace

• • 1. Procedure

This procedure shall be followed to determine the grease, oil and binder content.

Unplait a representative length of the packing, not less than a mass of 5 g, taking care to collect all the pieces which are dislodged.

Place the extraction thimble fitted with the fritted glass plate in the weighing bottle and, with the lid offset, place in the circulating oven at 105 °C to 110 °C for 1h. Remove from the oven, replace the lid and place the weighing bottle containing the extraction thimble and fritted glass plate in the desiccator and allow to cool to room temperature.

Remove from the desiccator and weigh to the nearest 0.1 mg using the balance (W1).

Transfer the prepared sample to the extraction thimble and replace the weighing bottle with the lid offset containing the extraction thimble, fritted glass plate and the sample to the oven at 105 °C to 110 °C for 1 h. Remove the weighing bottle and contents from the oven, replace the lid and place it in the desiccator and allow it to cool to room temperature. Remove the weighing bottle containing the thimble, fritted glass plate and sample from the desiccator and weigh them to the nearest 0.1 mg using the balance (W2).

Insert the extraction thimble fitted with the fritted glass plate and sample into the Soxhlet extractor. Pour 300 mL to 400 mL of petroleum spirit into the boiling flask. Assemble the boiling flask, Soxhlet extractor and condenser and subject the sample to extraction for 1 h.

Dry the evaporating dish in the oven at 105 °C to 110 °C, cool to room temperature and weigh to the nearest 0.1mg using the balance (W3).

At the end of 1 h, transfer the solution from the Soxhlet apparatus to the evaporating dish and evaporate off the solvent. Place the evaporating dish and its contents in the oven for 30 min at 105 °C to 110 °C then remove and cool it to room temperature.

Weigh the evaporating dish and contents to the nearest 0.1mg using the balance (W4).

• • 1. Evaluation

Calculate the percentage grease, oil and binder content by mass P from the Formula (A.1)

(A.1)

where W1, W2, W3 and W4 are the masses as described in A.1.4.

• 1. Determination of size

To determine the size of the packing the following procedure shall be adopted:

Cut a single test piece from the packing approximately 100 mm long. Measure the thickness in the two directions at a minimum of five evenly spaced positions along the length of the test piece. Measure the thickness to the nearest 0.1 mm using a suitable caliper or micrometer gauge having an anvil width of at least 3 mm.

Do not apply pressure to the packing when carrying out measurements.

• 1. Determination of density

To determine the density of the packing the following procedure shall be adopted:

For packing sizes up to and including 25 mm cross section size measure a 100 ± 0.2 mm length of packing. For packing with a cross section size greater than 25 mm the sample shall be such that the mass is not less than 300 g or the length less than 100 mm.

Measure the length of the sample using a suitable apparatus, to an accuracy of 0 ± 0.2 mm.

Measure the cross-section of the sample by the method detailed in A.2.

Weigh the sample on a suitable balance to the nearest mg.

Calculate the volume of the sample.

Divide the mass of the sample in grams by the volume in cubic centimetres to give the density of the packing in grams per cubic centimetre.

NOTE See also DIN 53830‑3.

• 1. Determination of tensile strength and elongation at break of packing yarns

Tensile strength and elongation at break shall be determined in accordance with EN ISO 527 or
ASTM D2256 using a Zwick Universal Testing Machine or similar, using clamping jaws so designed as to prevent slipping of the sample.

The sample length shall be 300 mm and it shall be extended at a velocity of 300 mm/min.

• 1. Determination of shrinkage on packing yarns

The shrinkage of yarns is shall be determined in accordance with ISO 18067.

100 cm samples are placed in a hot air oven for 15 min and 280 °C.

After 15 min / 280°C the length of the samples are measured.

The difference of the length in percent is the shrinkage value.

• 1. Determination of creep resistance of packings

One packing ring in the size 40 × 56 × 8 mm with a 45° cut shall be located in a simulated stuffing box with a minimum radial clearances of 0.2 mm and standard surface roughness Ra ≤ 1 μm. The device should be fitted with instrumented gland bolts to measure the stress loss.

Apply an initial stress of 25 MPa on the packing by means of a gland follower.

Hold for 5 min and retighten to 25 MPa again.

After 4 h at this condition record the compression and gland pressure loss of the packing set.

Reduce the stress to zero and uninstall the packing ring.

Report the creep as the value of axial stress loss in %.

1. 
   (normative)
   
   Information to be supplied by the purchaser

The following information shall be supplied by the purchaser in his enquiry or order:

a) type of packing (see Table l),

b) dimensions of the packing, cross-section and either length or weight,

c) if required as rings (see Clause 4).

Bibliography

[1] EN ISO 4797, Laboratory glassware - Boiling flasks with conical ground joints (ISO 4797)

[2] ISO 4793, Laboratory sintered (fritted) filters — Porosity grading, classification and designation

[3] BS 572, Specification for interchangeable conical ground glass joints

[4] BS 2071, Specification for Soxhlet extractors

[5] DIN 53830, Testing of Textiles; Determination of linear density of single and plied yarns; simple yarns and plied yarns, textured yarns, short length method

[6] EN ISO 527‑1, Plastics - Determination of tensile properties - Part 1: General principles (ISO 527-1)

[7] ASTM C561, Standard Test Method for Ash in a Graphite Sample

[8] ASTM D4239, Standard Test Method for Sulfur in the Analysis Sample of Coal and Coke Using High- Temperature Tube Furnace Combustion

[9] ASTM D4327, Standard Test Method for Anions in Water by Chemically Suppressed Ion Chromatography

[10] ASTM D5373, Standard Test Methods for Determination of Carbon, Hydrogen and Nitrogen in Analysis Samples of Coal and Carbon in Analysis Samples of Coal and Coke

[11] REACH (EU Registration, Evaluation, Authorisation and Restriction of Chemicals Regulation) – Annex XVII Restricted Substance List