Recommended Practice for Guarding of Pumping Units

API RECOMMENDED PRACTICE 11ER THIRD EDITION, NOVEMBER 2009

REAFFIRMED, JULY 2020

Recommended Practice for Guarding of Pumping Units

Upstream Segment

API RECOMMENDED PRACTICE 11ER THIRD EDITION, NOVEMBER 2009

REAFFIRMED, JULY 2020

Special Notes

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Classified areas may vary depending on the location, conditions, equipment, and substances involved in any given situation. Users of this recommended practice (RP) should consult with the appropriate authorities having jurisdiction.

Users of this RP should not rely exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.

API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations to comply with authorities having jurisdiction.

Information concerning safety and health risks and proper precautions with respect to particular materials and conditions should be obtained from the employer, the manufacturer or supplier of that material, or the material safety datasheet.

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Copyright © 2009 American Petroleum Institute

Foreword

This recommended practice (RP) is under the jurisdiction of the API Subcommittee 11, Subcommittee on Field Operating Equipment.

It is intended that this RP provide a guideline for the guarding of moving parts of oil well pumping units. It is based on knowledge and experience gained through the application of guards for pumping units by the production segment of the petroleum industry over a period of many years.

In preparing this RP, the group responsible has selected and extracted specifications and recommendations from the following publications: ANSI A1264.1:2007, Safety Requirements for Workplace Walking/Working Surfaces and Their Access; Workplace, Floor, Wall and Roof Openings; Stairs and Guardrails Systems and ANSI B15.1:2000, Safety Standard for Mechanical Power Transmission Apparatus.

Metric (SI) conversions of and U.S. customary (USC) units are included throughout the text as parenthesized numbers. The following factors were used in making these conversions:

1. inches (in.) were converted to millimeters (mm) by multiplying inches by 25.4, and rounding to one place to right of decimal point;

   
   

2. pounds per linear foot (lb/ft) were converted to kilograms per meter (kg/m) by multiplying by 1.448164 and rounding to two places to right of decimal point;

   
   

3. pounds (lb) were converted to kilograms (kg) by multiplying by 0.4535924 and rounding to two places to right of decimal point.

Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.

Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specification.

Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the specification.

This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001.

Suggested revisions are invited and should be submitted to the Standards Department, API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001, standards@api.org.

iii

Contents

Page

1. Introduction 1

   1. Purpose 1

   2. Scope 1

2. Types of Guarding to be Used on Pumping Unit 1

   1. General 1

   2. Enclosures and Guardrails 1

   3. Location 1

3. Items to be Guarded 2

   1. General 2

   2. Sheaves and Belts 2

   3. Cranks, Counterweights, and Air Counterbalance Tanks 2

   4. Flywheels 2

   5. Horsehead and Carrier Bar 2

4. Requirements for Guarding 2

   1. General 2

   2. Enclosures 2

   3. Guardrails 5

   4. Guarding by Location 5

5. Equivalent Safety 5

6. Caution Signs and Color Coding 6

   1. General 6

   2. Signs 6

   3. Color Coding 6

7. Pumping Unit Brake 6

   1. Accessibility 6

   2. Brake Use 6

   3. Securing 6

8. Ladders and Platforms 6

   1. General 6

   2. Design Requirements 7

   3. Cages 7

   4. Landing Platforms 8

Annex A (informative) Examples of Guarding Equipment 9

Bibliography 17

Figures

1. Distance to Moving Part Requirements for Enclosures 3

2. Measurement of Distance Requirements for Enclosures Listed in Figure 1 4

3. Method of Measuring Opening “A” in Figure 1 4

1. Example of Belt Guard 9

2. Example of Counterbalance Guard 10

3. Example of Flywheel Enclosure 11

4. Examples of Horsehead Guards 12

5. Example of Color Code Application 13

   v

   Page

6. Rail Ladder with Bar Steel Rails and Round Steel Rungs 14

7. Clearance for Unavoidable Obstruction at Rear of Fixed Ladder 15

8. Offset Fixed Ladder Sections 15

9. Basket Guard Specifications 16

vi

Recommended Practice for Guarding of Pumping Units

1. Introduction

   1. Purpose

      
      

      This recommended practice (RP) provides a reference or guide for the design, manufacture, and installation of guards for oil well pumping units. It is based on practices which experience has shown to be functionally safe and practical.

      
      

   2. Scope

      
      

      This RP is intended to provide safeguards for all persons who are required to work around or on oil well pumping units.

      
      

      1. These safeguards should prevent bodily injury from contact with moving parts by anyone inadvertently walking into, falling, slipping, tripping, or similar action. The safeguards should also prevent injury from reasonable or predictable breakage of any of the component parts.

         
         

      2. It is anticipated that persons who will be exposed to the hazards involved with the moving parts of a pumping unit are adults who are able-bodied and physically capable of performing useful work; they may be expected to be of normal intelligence and able to act with reasonable decorum and caution. They may also be expected to be aware of the potential hazards involved. The general public normally will not have access to the area where pumping units are located. Pumping units generally are in rural and fairly remote locations on private leases where the public would be trespassing.

         
         

      3. Where unattended locations present close exposure to a community of people, safety barriers, such as provided by a totally enclosed and locked perimeter, may be required (see 4.4.1.3).

      
      

2. Types of Guarding to be Used on Pumping Unit

   1. General

      
      

      The general types of guards include those listed as follows or combinations thereof.

      
      

   2. Enclosures and Guardrails

      
      

      Enclosures usually provide the greatest degree of protection against moving parts of mechanical equipment. Guardrails sometimes offer less effective protection than enclosures of proper dimension and the use of guardrails shall be confined to protecting against slow moving equipment such as cranks, counterweights, air counterbalance tanks, and horseheads. Both enclosures and guardrails should be strong enough to withstand the impacts and loadings imposed upon them without collapsing against the moving mechanism they protect against, and their dimensions should be within the limits prescribed in Section 4.

      
      

   3. Location

This refers to equipment which, because of its location, is not accessible to employees performing normal operating or maintenance procedures. Where a hazard would exist during maintenance, the equipment should be shut down and all power locked out or the equipment guarded in accordance with 4.2 or 4.3.

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