Translated from the Korean original. Read the original
Buffer Replacement Records to Reduce Periodic Inspection Findings
· 13 min read
- Periodic elevator inspection
- Buffer replacement
- PU Buffer
- Oil Buffer
- Model name
- Component safety certification (부품안전인증)
- Replacement records
Key points
- Buffer replacement records must connect the physical component with its documents by recording elevator identification, installation location, model names before and after replacement, the basis for application, and work results together.
- Distinguish between elastomer condition for PU Buffers and hydraulic operation-related condition for oil Buffers in the records, while following the technical documents for the relevant model for verification methods and assessment criteria.
- The company’s certification history and certification verification for the installed model are separate matters, so the application suitability of a replacement must not be explained solely by the year in which the product range obtained certification.
- Distinguish between available test items and actual test results, and connect only documents with verified test subjects, conditions, and assessment criteria to the relevant Buffer as supporting evidence.
- Records alone do not guarantee a satisfactory inspection outcome, and when site conditions differ from the documents, the results of checking and addressing those differences must also be recorded.
⚠ CautionThis article explains general inspection criteria. For maintenance decisions on a specific installation, please also check that model’s manual and inspection criteria.
Contents▾
- 1.Buffer replacement records must explain the installed product
- 2.Organize the models before and after replacement for comparison at a glance
- 3.Record application conditions by connecting product documents with site conditions
- 4.Record PU Buffers with a focus on the elastomer and mounting condition
- 5.Record hydraulic operation-related information separately for oil Buffers
- 6.Distinguish certification history from documents for the model actually installed
- 7.Manage available test items separately from actual test results
- 8.Use the same record group for inspection preparation and handover
- 9.The conclusion for Buffer records is that they must explain the current condition
Buffer replacement records must explain the installed product
Record what was replaced, beyond the fact of replacement
When preparing for a periodic elevator inspection, Buffer replacement records that merely report completion of the work are insufficient. They must be able to explain what product is currently installed and on what basis it was applied.
A Buffer is a safety component that absorbs the impact energy of the car or Counterweight (CWT) at the bottom of the Hoistway. Its operation is difficult to observe during normal service, so its appearance and documents must be examined together.
If the work log only states ‘Buffer replacement completed,’ it is difficult to identify the product type, installation location, or whether the model changed. When personnel change, even whether the replacement was the same product must be checked again.
The records should focus on identification of the physical component, the basis for the application decision, and the results of checks after replacement. These three elements must be connected to answer questions consistently during inspection.
The record items in this article are a practical way to organize information for site handovers and inspection preparation. This does not mean that every item is uniformly required as a statutory submission document; the documents actually required must be checked for the relevant site.
Inspection preparation starts with agreement between records and site conditions
Even if a document contains a model name, the explanation breaks down if it differs from the marking on the physical component. Conversely, even if the component appears to be in good condition, additional verification is needed if the conditions reviewed for its application cannot be identified.
During inspection preparation, it is better to check the installed condition and compare it with the records before preparing the paperwork. Start by checking whether the location, quantity, markings, and fastening condition match the records.
If Buffers are installed on both the car side and the Counterweight (CWT) side, record the locations separately. Do not combine models and work details into a single line simply because the components belong to the same elevator.
Label photographs with the location and time taken, and identify which physical component each document concerns. The appropriate level of detail allows another person to locate and check the same component even when the person responsible for the site is absent.
Organize the models before and after replacement for comparison at a glance
Identify the elevator and installation location first
Grouping records by building name alone can mix documents for multiple elevators. Distinguish them by placing the elevator identification used on site and the installation location at the beginning of the document.
Rather than using a broad location such as ‘inside the Pit,’ indicate the car side or Counterweight (CWT) side so that the record can be compared with the physical component. If several components occupy the same location, establish markings to distinguish each one.
It is advisable to read and photograph the old model name before removal. If the nameplate is damaged, distinguish between the parts that can be read and those that could not be verified, and record how existing documents were used to supplement the information.
For the new product, check the markings on the component actually installed rather than photographing only the packaging label. Without identification that connects the packaging to the physical component, a packaging photograph alone makes it difficult to establish the installed model.
| Record group | Information to retain | What it verifies |
|---|---|---|
| Site identification | Elevator identification, installation location, identification of the physical component | Which component belongs to which elevator |
| Product before replacement | Model name, identification, condition photographs, reason for removal | What was replaced and why |
| Product after replacement | Model name, identification, installation photographs | What was actually installed |
| Basis for application | Technical documents, certification-related documents, review details | Which conditions were checked for application |
| Work results | Work date, person responsible, items checked, follow-up actions | What was checked after replacement |
Distinguish replacement with the same model from a model change
Even if the model names before and after replacement are the same, retain the new product’s identification and work results separately. Copying existing records can mix the histories of the removed component and the new one.
If the model name changed, record the reason and connect the review documents. State reasons actually verified, such as discontinuation, a supply change, or a review of application conditions, and do not fill gaps with assumptions.
Similar names or identical appearances are unlikely to provide sufficient grounds for application suitability. Record which documents were used to compare the elevator’s conditions with the product’s scope of application.
Record application conditions by connecting product documents with site conditions
Do not base the replacement decision solely on external dimensions
A Buffer is not a component to select merely by checking whether it fits the installation space. Its suitability for the elevator’s operating conditions, load conditions, and mounting conditions must also be reviewed.
In the replacement review document, connect the documents used to verify site conditions with the technical documents for the new model side by side. Where values are needed, copy them from verified drawings or documents and indicate when those documents were prepared.
First check whether the car side and Counterweight (CWT) side can be treated as having the same conditions. Do not arbitrarily decide that a model applied to one side can also be used on the other.
If the product height or mounting method changes, the surrounding space, contact relationships, supports, and fastenings must be examined again. The component’s own performance and its condition after installation must each be checked.
Leave matters without a basis for judgment as tasks to verify
When site documents and supplier documents differ, do not merely record which one was selected. Retain the details of the difference, the party asked to verify it, the response, and the final judgment together.
Skipping the application review for a new model simply because the product was previously used makes the change difficult to explain. Past use is reference information and does not replace the basis for applying the current model.
Do not treat matters that could not be verified as ‘suitable’; separate them as unverified items. Assigning a person responsible for verification and identifying the documents needed can reduce repeated questions during the next task.
In the final records, distinguish the roles of the person who reviewed the application and the person who checked the installed condition on site. Completion of the document review and completion of the installation check are different results.
Record PU Buffers with a focus on the elastomer and mounting condition
Retain information that allows comparison of material deformation
A PU Buffer absorbs impact energy through deformation of a polyurethane elastomer. Along with product identification, record the checks of the elastomer’s appearance, shape, and support condition.
If cracks, tears, compression, or deformation are visible, record their locations and characteristics. Rather than writing only ‘aged,’ it is useful to connect photographs and descriptions showing what change was observed on which surface.
Record surface contamination separately from material damage. Indicating whether the condition was checked after wiping, or whether contamination prevented observation of some areas, makes the photographs clearer.
Appearance photographs alone cannot establish elastic properties or energy absorption performance. Separate observations from performance judgments, and if further verification is needed, review it according to the documents for the relevant model.
Make the condition immediately after replacement a reference for the next check
After installing a new PU Buffer, retain photographs showing both its shape and mounting condition. It is helpful to establish consistent photographic angles so that changes can be compared during later checks.
Also record the condition of the supporting surface and fastenings. If only the elastomer was replaced and a problem remains in the surrounding support, the phrase ‘replacement completed’ alone cannot adequately explain site conditions.
Check for foreign matter deposited during the work and interference with surrounding components. Follow the product documents for verification methods, and do not conclude that the product is normal through an arbitrary compression test.
Do not force hydraulic-related items into PU Buffer records. Mark unused items as not applicable to distinguish omitted items from those that do not apply because of the structure.
Record hydraulic operation-related information separately for oil Buffers
Record oil leakage traces together with the condition at the time of checking
An oil Buffer absorbs impact energy through hydraulic resistance. Replacement records should retain information on appearance as well as the operating parts and hydraulic-related conditions that the relevant model’s instructions require checking.
If oil traces are visible, record their location and extent and connect the photographs. Also record cleaning and rechecking history so that contamination left from previous work can be distinguished from traces that have reappeared.
If the design allows the oil condition or quantity to be checked, use the method specified in the manufacturer’s documents. Verification methods may differ by product, so do not directly apply another model’s inspection method.
Where information about the oil used is needed, record it on the basis of verified documents for the relevant model. Do not infer the oil type or conclude that oils can be mixed simply because an oil is familiar on site.
Record the condition of moving parts and the scope of checks
Check the surfaces, contamination, damage, and return condition of operating parts within the scope instructed by the model documents. Record both the items checked and the methods used.
Do not carry out arbitrary impact or compression on site to determine an oil Buffer’s condition. If a functional check is needed, the prescribed procedure and working conditions must be confirmed first.
| Category | Information to retain for PU Buffers | Information to retain for oil Buffers |
|---|---|---|
| Main observation targets | Elastomer cracks, tears, shape changes | Oil leakage traces, operating-part surfaces and damage |
| Documents for condition comparison | Photographs of the shape immediately after replacement and subsequent changes | Condition before and after cleaning, and recheck records |
| Model-specific verification documents | Instructions on material condition and mounting | Instructions on checking oil and operating parts |
| Common records | Model name, identification, location, basis for application | Model name, identification, location, basis for application |
This table distinguishes the focus of the records. It does not replace individual product acceptance criteria or inspection procedures, and the technical documents for the relevant model must be used for the final judgment.
Distinguish certification history from documents for the model actually installed
The year a product range obtained certification is background information
D&D’s Buffer product line includes PU Buffers and oil Buffers. The company’s component safety certification (부품안전인증) history includes PU Buffers in 2023 and oil Buffers in 2024.
This history is background information about the product ranges. To verify a specific model installed on site and its scope of application, certification-related documents that identify the relevant product must be compared separately.
Recording only the year certification was obtained does not show which model’s documents were checked. Connect the product identification and scope of application shown in the actual documents to the installed component in the records.
For certification-related document numbers and model names, use the markings verified in the original documents. Entering them from memory or taking them from documents for a similar product can break the connection between the physical component and the documents.
Check the documents’ scope of application and revision history
If a document lists both a representative model name and detailed variants, check which scope includes the installed component. Do not judge them to be within the same certification scope simply because part of the name matches.
If the model markings differ between supply documents and the physical component, do not arbitrarily standardize them into one. Ask the manufacturer or supplier to verify the relationship and connect the response documents to the replacement records.
When documents are updated or supplemented, do not retain only the latest version and delete the basis for previous reviews. It must be possible to trace what was checked at the time of the work and what changed afterward.
The existence of certification-related documents alone does not explain the installation condition on site. Include the application-condition review and the results of checks after replacement in the same record group to complete the sequence of judgment.
Manage available test items separately from actual test results
Do not present equipment ownership as a product performance result
D&D’s test tower, completed in 2025, has a rubber compression testing machine (10ton) and a device displacement compression testing machine (15ton). This is information about test equipment.
Equipment names and capacities alone do not establish the test scope or assessment results for a specific Buffer. To determine which tests can be applied to the relevant model, the test subject and conditions must be verified.
In replacement records, store responses confirming available test items separately from actual test reports. Recording a test consultation as a completed test changes the level of supporting evidence.
When enquiring about testing, provide the model name and test purpose first. What is to be verified must be clear before the required samples, test methods, and scope of use of the results can be discussed.
Connect test documents only after verifying the subject and conditions
When a test report is received, check the model and identification of the product tested. If the results concern another sample in the same product range, the extent to which they can be used for this replacement must be reviewed separately.
Read the test conditions, measurement items, and assessment criteria together. Do not expand the interpretation to mean that suitability for site application or all functions have been verified simply because numerical values are provided.
| Document status | Wording to record | Supporting evidence to retain together |
|---|---|---|
| Equipment ownership information verified | Relevant test equipment information verified | Equipment information documents |
| Test application consultation completed | Available test scope for the relevant model verified | Response identifying the model and purpose |
| Testing completed | Test conducted on the specified subject under the specified conditions | Documents identifying the test subject, conditions, and results |
| Site application review completed | Scope of use of test documents reviewed | Review details comparing them with site conditions |
If no test was conducted, record it as not conducted. Whether test documents are always needed should be checked according to the individual circumstances, but the basic principle is not to present results that have not been obtained as though they exist.
Use the same record group for inspection preparation and handover
Compare the physical component with the documents in sequence
For inspection preparation, first verify the location and identification of the installed Buffer. Then compare the replacement records, product technical documents, certification-related documents, and work results to ensure they refer to the same model.
Checking only a document list can miss a problem where a file exists but concerns another model. Whether the documents explain the current physical component matters more than their mere existence.
Store photographs of the overall installation condition separately from photographs of identification markings. This can reduce problems where the model name cannot be read in an overall photograph or the location cannot be determined from a nameplate photograph alone.
When preparing records, distinguish ‘verified,’ ‘unverified,’ and ‘not applicable.’ A blank field does not show whether something was unchecked or omitted, creating unnecessary questions during handover.
Record discrepancies and follow-up actions through to completion
If a mistyped model name, missing photograph, or document discrepancy is found, record the reason for correction and the evidence used for verification. It must be possible to distinguish whether the actual product changed or only the records were corrected.
If additional explanations or documents were requested during inspection, record the request and the documents submitted. This allows the next person responsible for the site to review the questions and the results of the response.
If a finding concerned the component’s condition, separate the fact that explanatory documents were submitted from the fact that site action was completed. Supplementing paperwork alone does not resolve a physical problem.
Store completed records by replacement date while organizing them so that the currently installed model can be found easily. It is useful to connect the current condition with past history without deleting earlier records.
The conclusion for Buffer records is that they must explain the current condition
Connecting the physical component with supporting evidence matters more than the volume of documents
Managing Buffer records to reduce findings during periodic elevator inspections starts with accurately explaining the product currently installed. The model name, installation location, basis for application, and verification results must be connected.
Record PU Buffers with a focus on elastomer condition and oil Buffers with a focus on hydraulic operation-related condition. An appropriate approach is to retain common identification items while adding checks suited to each structure.
Distinguish company certification history as background information and equipment ownership information as testing resources. Certification verification for a specific model and actual test results must be explained separately through the relevant documents.
Make the scope verified and remaining tasks clear
Records are not a means of guaranteeing inspection results. If there is a problem with site conditions, the necessary action must be taken, and if the basis for judgment is insufficient, additional manufacturer or supplier documents must be checked.
Completing the records when replacing a Buffer reduces the need to gather memories and scattered photographs just before inspection. Even when personnel change, checks can continue from the same physical component and the same supporting evidence.
In practice, a good record is a document that shows what has been verified and what remains outstanding, rather than one with every field filled in. That distinction becomes the starting point for the next check and replacement decision.
Frequently asked questions
- How should Buffer replacement records be organized for a periodic elevator inspection?
- Group the model names and identification before and after replacement, replacement reason, application review documents, installation photographs, and results of checks after the work by elevator and installation location. Organize them so that related documents can be found directly from the currently installed component, and also mark unverified matters and follow-up actions.
- What information should be recorded separately for PU Buffers and oil Buffers after replacement?
- For PU Buffers, record elastomer cracks, tears, shape changes, and support condition. For oil Buffers, record oil leakage traces, operating-part condition, and oil-related checks according to the model documents. Record common information, such as model name and installation location, for both types.
- How should the record be made if the removed component’s nameplate is damaged and the model name cannot be read?
- Photograph the damage and any readable markings, and mark the model name as unverified. When supplementing the information with previous replacement records or supply documents, connect the documents used for verification, and do not infer the model name from a similar appearance.
- Can photographs of the physical component be omitted if the delivery note contains the model name?
- A delivery note describes the product supplied but does not show its actual installation location or condition. It is advisable to photograph the installed component’s identification markings and installation condition to connect the delivery documents with the physical component.
- Can replacement records not be finalized without a test report?
- Whether a test report is needed must be reviewed according to the product, the site’s application conditions, and the purpose of verification. If no test was conducted, record it as not conducted, and do not substitute test equipment information or a response confirming test availability for actual test results.
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