ISO/DIS 5211:2025(en)

ISO/TC 153/WG 1

Date: 2024-12-27

Industrial valves — Part-turn actuator attachments

Robinetterie industrielle — Raccordement des actionneurs à fraction de tour

© ISO 2025

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Contents

Foreword iv

Introduction v

1 Scope 1

2 Normative references 1

3 Terms and definitions 1

4 Maximum flange torques 2

5 Flange dimensions 3

6 Designation 6

7 Dimensions and torques 7

7.1 General 7

7.2 Drive by key(s) 8

7.3 Drive by parallel or diagonal square head 11

7.4 Drive by flat head 12

7.5 Drive by improved flat head 14

7.6 Drive by involute spline 15

7.7 Drive by bi-square 17

8 Position of driven components at interface below part-turn actuator 18

8.1 Drive by key(s) 18

8.2 Drive by parallel or diagonal square head or bi-square 20

8.3 Drive by flat head 21

9 Dowel pins 21

Annex A (informative) Explanation of calculations 22

Annex B (normative) Dimensions of keys and keyways 24

Bibliography 30

Foreword

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The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

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This document was prepared by Technical Committee ISO/TC 153, Valves, in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 69, Industrial valves, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).

This third edition cancels and replaces the second edition (ISO 5211:2023), which has been technically revised.

The main changes are as follows:

— dimensions and tolerances for keys and keyways were added in a new Annex B;

— a reference to the new Annex B was added in 7.2;

— editorial changes were made.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

The purpose of this document is to establish certain basic requirements for the attachment of part-turn actuators, in order to define the interface between actuator and valve.

This document is, in general, considered in conjunction with the specific requirements which may be agreed between the parties concerned.

NOTE 1 In this document, the term “valve” can also be understood to include “valve with an intermediate support” [see Figure 1 b)].

NOTE 2 When a combination of a multi-turn actuator and separate part-turn gearbox is coupled to form a part-turn actuator, the multi-turn attachment to the gearbox is in accordance with ISO/DIS 5210:2025^[1], Figures 1 c) and 1 d). A combination of a multi-turn actuator with integral part-turn gearbox supplied as a part-turn actuator is in accordance with Figures 1a) and 1b).

Key

Figure 1 — Interface between part-turn actuator and valve

Industrial valves — Part-turn actuator attachments

This document specifies requirements for the attachment of part-turn actuators, with or without gearboxes, to industrial valves.

The attachment of part-turn actuators to control valves in accordance with the requirements of this document is subject to an agreement between the supplier and the purchaser.

This document specifies:

— flange dimensions necessary for the attachment of part-turn actuators to industrial valves [see Figures 1 a) and 1 c)] or to intermediate supports [see Figures 1 b) and 1 d)];

— driving component dimensions of part-turn actuators necessary to attach them to the driven components;

— reference values for torques for interfaces and for couplings having the dimensions specified in this document.

The attachment of the intermediate support to the valve is out of the scope of this document.

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 273, Fasteners — Clearance holes for bolts and screws

For the purposes of this document, the following terms and definitions 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/

3.1

actuator

any device designed for attachment to a general-purpose industrial valve in order to provide for the operation of the valve

Note 1 to entry: The device is designed to operate using motive energy which may be electrical, pneumatic, hydraulic, manual, etc., or a combination of these. Movement is limited by travel, torque (3.5) and/or thrust.

3.2

multi-turn actuator

actuator (3.1) which transmits torque (3.5) to the valve for at least one revolution and may be capable of withstanding thrust

Note 1 to entry: An actuator may be a combination of a multi-turn actuator and multi-turn gearbox (3.4).

3.3

part-turn actuator

actuator (3.1) which transmits torque (3.5) to the valve for a rotation of one revolution or less and does not have to withstand axial thrust

Note 1 to entry: A part-turn actuator may be a combination of a multi-turn actuator (3.2) and part-turn gearbox (3.4).

3.4

gearbox

any mechanism designed to reduce the torque (3.5) required to operate a valve

3.5

torque

turning moment transmitted through the mounting flanges and connection components

Note 1 to entry: Torque is expressed in newton-metres.

The flange torque shall comply with the values listed in Table 1 which represent the maximum torques which can be transmitted through the mounting flange.

Table 1 — Maximum flange torque values

The values specified in Table 1 have been defined on the basis of bolts in tension only at a stress of 290 MPa and a coefficient of friction of 0,2 between the mounting interface. All variations in these defined parameters lead to variations of the transmittable torque values. See Annex A for more details on the calculation method.

The selection of flange types for a particular application should take into account the additional torques that may be generated because of inertia or other factors.

Flanges for part-turn actuator attachments shall comply with the dimensions shown in Figure 2 and given in Table 2. The method of attachment shall be by means of studs, screws or through bolting.

Holes for the studs, screws or bolts shall be equi-spaced and positioned off-centre (see Figure 3 and Table 3) and shall conform to the requirements of ISO 273.

The flange on the valve shall have a recess corresponding to the diameter d₂. A spigot on the part-turn actuator is optional.

The minimum values for dimension h₂ shown in Table 2 apply to flanges having material of proof stress R_e ≥ 200 MPa. The minimum values for dimension h₂ applied to flanges having materials of proof stress R_e ≤ 200 MPa shall be agreed between manufacturer and purchaser. The minimum values for dimension h₃ shall be at least 1 × d₄.

Dimension d₁ has been based on providing sufficient landing for the nuts and bolt heads where applicable. Such landing is defined as a radius from the bolt hole centre with the dimension (d₁ − d₃) / 2, and is a minimum. The flange shape of both valve and actuator outside these areas of landing is left to the option of the manufacturer.

The dimensions and bolting material are based on bolts in tension at a maximum stress of 290 MPa. On agreement, between the manufacturer/supplier and purchaser, bolting material with different tensile strength can be used, with no dimensional changes but with potential variation of the transmittable torque.

Above flange type F60 alternative dimensions and/or torque ratings may be used on agreement between manufacturer/supplier and purchaser.

Figure 2 — Flange dimensions

Table 2 — Flange dimensions

Dimensions in millimetres

Figure 3 — Position of holes

Table 3 — Position of holes

Part-turn valve actuator attachments shall be designated as follows:

— flange designation:

— flange type as per Table 1;

— a capital letter for spigot identification:

— Y with spigot;

— N without spigot;

— drive designation:

— an additional capital letter for drive identification:

— V for single-key drive;

— W for 90° two-key drive;

— X for 180° two-key drive;

— L for parallel square drive;

— D for diagonal square drive;

— H for flat head drive;

— G for improved flat head drive;

— S for involute spline;

— T for bi-square;

— the actual dimensions of the drive (in millimetres):

— dimension d₇ for key drives (see Figure 4 and Table 4);

— dimension s for square or flat drives (see Figure 5 or 6 and Table 5 or Figure 7 and Table 6);

— module m for involute spline (see Figure 9 and Table 8).

EXAMPLE  

ISO 5211 – F05 Y – V – 18, identifies a part-turn valve actuator attachment in accordance with this document, with F05 flange type, spigot and single-key drive with 18 mm diameter.

NOTE The designation is not a marking requirement.

To ensure that no interference can occur between the driving component and the driven component, the length of the driven component above the interface shall be limited so that there is a clearance between both parts.

The depth of engagement of the valve driven component into the actuator drive component and the surface area of contact between the faces of the actuator drive component and the faces of the valve driven component should be considered to ensure that the stresses caused by contact do not exceed the capability of the component materials. In some cases, it may be necessary to use materials with superior mechanical properties and/or to reduce the output torque of the actuator.

Dimensions of the drive components for key drive shall meet the requirements of Figure 4 and Table 4.

The values of d₇, h₄ and l₅ in Table 4 are based on single-key design up to 98 mm shaft diameter.

Where more than one key is required to transmit the torque, the dimensions in Table 4 shall still apply.

The key dimensions shall conform with those given in Annex B or any national standard.

The keyway(s) in the driving component shall correspond to the position of the key(s) supplied on the driven component as specified in 8.1, Figures 11, 12 or 13.

The key(s) shall be secured in position by suitable means.

Key

Figure 4 — Drive by key(s)

Table 4 — Dimensions and torques for drive by key(s)<Tbl_--></Tbl_-->

Dimensions in millimetres

Dimensions of drive components for square heads shall meet the requirements of Figures 5 or 6 and Table 5. The choice of d₈ and d₉ depends on the manufacturing process.

The square drive positions shall be as specified in 8.2, Figures 14 or 15.

Key

Figure 5 — Drive by parallel square head

Key

Figure 6 — Drive by diagonal square head

Table 5 — Dimensions and torques for drive by parallel or diagonal square head

Dimensions in millimetres

Dimensions of drive components for flat head drive shall meet the requirements of Figure 7 and Table 6.

The flat head drive position shall be as specified in 8.3 and Figure 16.

Key

Figure 7 — Drive by flat head

Table 6 — Dimensions and torques for drive by flat head

Dimensions in millimetres

Dimensions of drive components for improved flat head drive shall meet the requirements of Figure 8 and Table 7. The improved flat head drive position shall be as specified in 8.3 and Figure 16.

Key

Figure 8 — Drive by improved flat head

Table 7 — Dimensions and torques for drive by improved flat head

Dimensions in millimetres

Dimensions of drive components for involute spline shall meet the requirements of Figure 9 and Table 8.

NOTE 1 Involute spline is based on ISO 4156-1.

NOTE 2 Pressure angle of 30°, clearance with loose fit and half tooth height are basis for Table 8.

Key

Figure 9 — Drive by involute spline

Table 8 — Dimensions and torques for drive by involute spline

Dimensions in millimetres

Dimensions of drive components for bi-square shall meet the requirements of Figure 10 and Table 9. The choice of d₈ and d₁₂ depends on the manufacturing process.

Figure 10 — Drive by bi-square

Table 9 — Dimensions and torques for drive by bi-square

Dimensions in millimetres

One or two keys may be used. With the valve closed, the key(s) shall be located as shown in Figures 11, 12 or 13. If more than two keys are required, their position shall be subject to an agreement between the supplier and the purchaser.

NOTE The standard closing direction is clockwise, as viewed from above the interface.

Key

Figure 11 — Position of key on the driven component

Key

Figure 12 — Positions of 90° keys on the driven component

Key

Figure 13 — Positions of 180° keys on the driven component

With the valve closed, the flat sides of the square head drive component shall be located as shown in Figures 14 or 15.

Key

Figure 14 — Position of parallel square head driven component

Key

Figure 15 — Position of diagonal square head driven component

With the valve closed, the flat sides of the flat head drive component shall be located as shown in Figure 16.

Key

Figure 16 — Position of flat head driven component

Dowel pins across the interface between valve and actuator may be used in order to achieve an improved tolerance in positioning.

Size, number and position of dowel pins shall be agreed between supplier and customer. For flanges up to size F60, as a general guideline:

— should be positioned on the pitch circle diameter d₃;

— position should be in line or perpendicular to the valve closed position;

— diameter of the dowel pins should be the nominal value of d₄, but not larger than 30 mm.

WARNING — Dowel pins are not designed to transfer torque across the interface. A distinct load distribution can otherwise not be assumed.

1. 
   (informative)
   
   Explanation of calculations
   1. Basis of torque values for flange sizes

For each designated flange size, a maximum transmissible torque value is established by this document. For each flange size, geometrical design and sizing principles were established, where possible.

The calculation method, given in Formulae (A.1) and (A.2), establishes the maximum transmissible torque per flange size. The resulting torque values are supported by other calculation methods provided by existing standards.

Flanges with maximum transmissible torque values that diverge from this calculation method are established in the market.

Since the interface only transfers torque by static friction and the bolted connection is not designed for shear stresses, a safety against slipping can be derived with the defined bolt tensile stress of 290 MPa and specification of the coefficient of friction 0,2 using formulae:

(A.1)

and

(A.2)

where

NOTE This calculation was used to derive the maximum flange torque values in Table 1 and is not qualified for any design proofs; nor is it intended to replace engineering calculations defined by national standards or regulations.

• 1. Coefficient of friction of 0,2

Through national standards, regulations and experience within the valve industry, a coefficient of friction 0,2 in the contact area [interfaces (see Figure 1, keys 2 and 6)] of flanges between actuator and valve became established.

• 1. Tension stress bolts

The bolt quality, method of tightening and application factors are the basis for the bolt tension stress of 290 MPa.

This value is calculated using 90 % of the yield strength of a bolt quality (8.8) and assuming that the bolts are tightened with a torque wrench (tightening factor 1,6) and an application factor (1,25) for relaxation.

The bolt quality 8.8 defines

— R_m = 800 MPa, and

— R_e = 80 % × R_m = 640 MPa.

The tension stress of the bolt can be calculated as 290 MPa = R_e × 90 % / 1,6 / 1,25.

1. 
   (normative)
   
   Dimensions of keys and keyways
   1. Basis for keys and keyways dimensioning

With ISO R773:1969 being withdrawn, there is currently no International Standard defining keys and keyways available. Since for driven by key (see 7.2), keys and keyways are the means to transfer torque from the actuator to the valve, information on design and dimensions is given in this annex.

• 1. Key and keyway forms

Forms for key and keyway shall fulfil the requirements given in Figure B.1 to Figure B.3.

Keys and keyways according to low patterns are not described in this annex.

Bolts for retaining of keys, slants for disassembly of keys and holes for spiral pins are common with larger key sizes, but are not described in this annex.

NOTE 1 Length l_x according to form A, B or AB.

NOTE 2 and .

NOTE 3 Radius r of key = b/2.

Figure B.1 — Key forms

Figure B.2 — Keyway forms for valve shafts

NOTE Chamfer and radius [Figures B.3 a) and b)] are chamfered/rounded (at all edges).

Figure B.3 — Chamfering/rounding for key/rounding at base of groove

• 1. Dimensions and tolerances (cross section and design details)

The dimensions of the keys and keyways, as well as their acceptable deviations, shall be in accordance with those given in Tables B.1 and B.2.

Table B.1 — Dimensions and tolerances of keys, part 1

Dimensions in millimetres

Table B.2 — Dimensions and tolerances for keys, part 2

Dimensions in millimetres

Bibliography

[1] ISO 4033, Fasteners — Hexagon high nuts (style 2)

[2] ISO 4156‑1, Straight cylindrical involute splines — Metric module, side fit — Part 1: Generalities

[3] ISO/DIS 5210:2025,¹ Industrial valves — Multi-turn actuator attachments

[4] ISO 5115, Industrial valves — Part-turn valve actuation

[5] ISO 5640, Industrial valves — Mounting kits for part-turn valve actuator attachment

[6] ISO 22153, Electric actuators for industrial valves — General requirements

[7] ISO 22109, Industrial valves — Gearbox for valves

[8] ISO/CD 23097:2024,^[2] Industrial valves — Pneumatic part-turn actuators — General requirements

[9] ISO/R 773:1969,^[3] Rectangular or square parallel keys and their corresponding keyways (Dimensions in millimetres)

1. Under preparation. ↑

2. Under preparation. ↑

3. Withdrawn. ↑