---
title: "What Core Operating Specifications and Pitfall Prevention Points Should Be Followed for Installation of Eccentric Reducer at Centrifugal Pump Inlet?"
description: "The operation and maintenance supervisor of a chemical equipment importing enterprise encountered customs inspection objections and daily port detention loss of RMB 1200 due to incorrect installation of the eccentric reducer，and the equipment also developed cavitation noise failure. It is necessary to strictly follow operating specifications such as flat-top installation and levelness deviation ≤ 0.5mm/m. When rectifying，submit the original manufacturer's Chinese-English installation certificate..."
url: "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html"
language: "en"
type: "Q&A"
category: "Import Agency Q&A"
datePublished: "2026-07-19"
dateModified: "2026-07-19"
brand: "Zhongshen Trading China"
answerCount: 8
---

# What Core Operating Specifications and Pitfall Prevention Points Should Be Followed for Installation of Eccentric Reducer at Centrifugal Pump Inlet?

## Question

 I am an operation and maintenance supervisor at a chemical equipment importing enterprise in Shanghai. We just imported 12 horizontal centrifugal pumps from Germany last week. The temporarily hired outsourced technician had no experience in piping installation for imported pumps, and installed the matched eccentric reducer in the wrong direction. The pump frequently produces harsh cavitation noise when starting. Worse still, when customs carried out inspection at Yangshan Port last Wednesday, the on-site engineer pointed out that the installation did not comply with the original manufacturer's specifications and required rectification before release. Now the cargo has been detained at the port for 6 days, with a daily detention fee of RMB 1200. The end customer is pressing for the acceptance certificate, and my boss also puts pressure on me every day. I am too anxious to sleep, and I would like to ask for advice: from the two core perspectives of import compliance inspection and equipment operation and maintenance, how should the eccentric reducer at centrifugal pump inlet be installed to not only pass customs inspection smoothly, but also completely avoid cavitation and other equipment failures? 

## Answers
                            
### Answer 1 — Best Answer

There are three common installation mistakes in the industry: first，randomly selecting the eccentric direction and adopting "flat-bottom" installation for the eccentric reducer at the inlet of horizontal centrifugal pump，second，ignoring the levelness requirement，leading to piping deviation exceeding the equipment's allowable range，third，skipping air tightness test and starting the equipment directly after installation.

These mistakes will trigger a chain of negative reactions: wrong eccentric direction will cause gas accumulation at the pump inlet，leading to serious cavitation，which will damage the impeller in as short as 3 months and directly burn the motor in severe cases，meanwhile，during on-site customs inspection，non-compliance with original manufacturer's specifications will lead to determination of inconsistent declaration，triggering customs detention and port detention. According to the 2026 detention fee standard of Shanghai Port，the daily detention fee per container can reach RMB 1200，and the detention fee for a one-week delay exceeds RMB 8000. Excessive levelness deviation will cause uneven stress on the pump shaft，trigger high-frequency vibration and damage sealing parts.

For physical risk prevention，two core operations must be strictly implemented: **The eccentric reducer at the inlet of horizontal centrifugal pump must adopt "flat-top" installation** to avoid gas accumulation，**Control the levelness deviation within 0.5mm/m**，and calibrate section by section with a high-precision level. After installation，use the soapy water leak detection method to conduct air tightness test on all piping joints to ensure no leak points.

Exclusive loss mitigation tip: If installation error or customs inspection objection has occurred，immediately coordinate with the original manufacturer to issue a Chinese-English installation specification certificate，submit it to the customs for expedited re-inspection，and at the same time provide the customs inspection notice to the shipping company to apply for more than 50% reduction of detention fee，after equipment rectification，conduct a 1-hour no-load trial operation and record operating noise and vibration data as supplementary compliance proof.

**status:** accepted
**Author:** Victor Sun
**Date:** 2026-07-20

### Answer 2

The installation specification of eccentric reducer at centrifugal pump inlet is one of the core compliance bases for customs document review and inspection. If the installation parameters of the matched reducer are not included in the equipment technical specifications during declaration, or on-site installation does not match the document marking, it will directly trigger an early warning of inconsistent document and cargo, leading to problems such as declaration deletion and re-submission, valuation dispute and even customs detention.

Enterprises need to translate the English installation specification provided by the original manufacturer into Chinese, affix the special customs declaration seal, and submit it to the customs as an attached document. Meanwhile, clearly mark key parameters such as "Matched eccentric reducer adopts flat-top installation, levelness deviation ≤ 0.5mm/m" in the "Specifications and Model" column of the Import Goods Declaration Form. If inspection objection has occurred, immediately coordinate with the original manufacturer to issue an installation compliance certificate, apply for expedited re-inspection by customs, and submit the detention fee reduction application at the same time to avoid additional costs caused by process delay.

**status:** suggested
**Author:** Evelyn Li
**Date:** 2026-07-20

### Answer 3

The installation of eccentric reducer matched with imported centrifugal pump needs to be closely connected with port logistics nodes. Improper operation during temporary installation at the port will not only cause equipment damage, but also occupy terminal storage resources and extend detention time.

Enterprises need to plan the installation site in advance, give priority to bonded warehouses with equipment installation qualification for pre-installation, and avoid operation in open terminal areas. At the same time, negotiate with the shipping company to extend the free storage period.

If the deadline is exceeded due to installation rectification, you can submit the inspection rectification notice issued by the customs to apply for reduction of container detention fee and port detention fee. In addition, after installation, the equipment needs to be re-fixed with shock-proof packaging to ensure that piping joints do not loosen during subsequent inland transportation.

**status:** suggested
**Author:** Michael Zhang
**Date:** 2026-07-19

### Answer 4

The installation cost of eccentric reducer at centrifugal pump inlet can be included in the calculation of the customs dutiable value of imported equipment, but it needs to meet compliance conditions. If the installation service is provided by an overseas manufacturer, it is necessary to clearly distinguish the equipment price and the installation service fee during declaration, to avoid overestimated dutiable value caused by combined declaration, which increases the cost of import tariff and value-added tax.

Meanwhile, if the enterprise meets the applicable conditions of the 2026 VAT deferral policy of Shanghai Customs District, the value-added tax corresponding to the installation service can be included in the deferral scope to ease capital pressure. It should be noted that the certificate of installation cost needs to include detailed service content, expense breakdown and payment certificate, to ensure that a complete document chain can be provided during tax authority inspection, and avoid tax adjustment caused by missing certificates.

**status:** suggested
**Author:** Grace Wang
**Date:** 2026-07-19

### Answer 5

The installation of eccentric reducer at centrifugal pump inlet involves compliance of cross-border foreign exchange payment and receipt. If the installation service is provided by an overseas supplier, it is necessary to clearly mark "Installation Service Fee for Centrifugal Pump Matched Eccentric Reducer" in the SWIFT message, to avoid being included in the foreign exchange regulatory warning list due to vague purpose of payment and receipt.

Meanwhile, if RMB cross-border payment via CIPS is adopted, it is necessary to ensure that the payment certificate is consistent with the service content in the customs declaration and contract, so as to avoid settlement and reconciliation problems caused by mismatch between cargo right and capital flow. Enterprises need to include installation services in the subsidiary clauses of the trade contract in advance, clarify the service content, fee standard and payment nodes, to ensure that foreign exchange payment and receipt operations comply with the relevant regulations of the State Administration of Foreign Exchange.

**status:** suggested
**Author:** Cindy Chen
**Date:** 2026-07-19

### Answer 6

In the trade contract for imported centrifugal pumps, it is necessary to clearly define the installation specifications and acceptance standards of the eccentric reducer, so as to avoid equipment failure disputes caused by the manufacturer's failure to provide clear installation guidance. An "installation compliance umbrella clause" should be added to the contract: if equipment damage or customs inspection failure is caused by incorrect installation specifications provided by the manufacturer, the manufacturer shall bear the port detention fee, rectification fee and equipment maintenance fee.

At the same time, the manufacturer should be required to issue a Letter of Indemnity (LOI) for installation compliance, which is one of the core basis for equipment acceptance. If a dispute has occurred, immediately start the verification of the force majeure clause. If the delay is caused by the manufacturer's failure to provide installation guidance in time, you can claim relevant losses from the manufacturer according to the contract.

**status:** suggested
**Author:** Daniel Xu
**Date:** 2026-07-19

### Answer 7

When customs inspects the installation of eccentric reducer at centrifugal pump inlet on site, it mainly checks three core indicators: eccentric direction, levelness and piping tightness. It is necessary to prepare tools such as level meter and air tightness detector in advance, and cooperate with customs engineers for on-site testing. If wrong eccentric direction installation is found (such as flat-bottom installation), it is necessary to adjust and re-fix immediately, and explain to the customs that the adjustment is based on the original manufacturer's installation specifications.

If the piping is not tightly sealed, the sealing gasket needs to be replaced on site and the pressure test re-conducted to ensure that the test data meets the technical requirements of the equipment. In addition, it is necessary to sort out the original manufacturer's installation manual, test report and other materials in advance, to avoid prolonging the inspection time due to incomplete materials.

**status:** suggested
**Author:** Andy Guo
**Date:** 2026-07-19

### Answer 8

After the installation of eccentric reducer at centrifugal pump inlet is completed, it needs to be fixed with special packaging that meets international transportation standards, to avoid loosening or damage of piping joints during subsequent transportation. The piping joints should be wrapped with high-density EVA buffer material, and the overall frame of the equipment should be reinforced with steel strips to ensure that the impact resistance of the packaging meets the ISTA 3A standard.

If the equipment needs to be transported long-distance inland, warning signs such as "Fragile, Do Not Invert, Piping Installed Handle With Care" should be marked on the outside of the packaging. At the same time, the loading and unloading responsibility of the carrier should be clearly defined in the transportation contract, to avoid damage to the installed piping caused by rough handling. In addition, photo materials before and after packaging should be retained as core evidence for subsequent claims.

**status:** suggested
**Author:** Linda Gao
**Date:** 2026-07-19

## Related Categories
- [Export Agency Q&A](https://www.sh-zhongshen.com/en/qa/cat-export-agency/)
- [Export Tax Rebate Q&A](https://www.sh-zhongshen.com/en/qa/cat-export-tax-rebate/)
- [Customs Declaration Q&A](https://www.sh-zhongshen.com/en/qa/cat-customs-declaration/)
- [Freight Forwarding Q&A](https://www.sh-zhongshen.com/en/qa/cat-freight-forwarding/)
- [Forex Settlement Q&A](https://www.sh-zhongshen.com/en/qa/cat-forex-settlement/)
- [Entrepôt Trade Q&A](https://www.sh-zhongshen.com/en/qa/cat-entrepot-trade/)
- [General Trade Q&A](https://www.sh-zhongshen.com/en/qa/cat-general-trade/)

## Related Resources
- [Trade Services](https://www.sh-zhongshen.com/en/services/)
- [Trade Cases](https://www.sh-zhongshen.com/en/cases/)
- [Trade Wiki](https://www.sh-zhongshen.com/en/wiki/)
- [Trade Class](https://www.sh-zhongshen.com/en/guide/)
- [Global Trade Services](https://www.sh-zhongshen.com/en/country/)

## Structured Data

```json
[
    {
      "@context": "https://schema.org",
      "@type": "QAPage",
      "inLanguage":"en", 
      "isPartOf": { "@id":"https://www.sh-zhongshen.com/en/#website" }, 
      "publisher":{ "@id":"https://www.sh-zhongshen.com/en/#organization" },
      "mainEntity": {
        "@type": "Question",
        "name": "What Core Operating Specifications and Pitfall Prevention Points Should Be Followed for Installation of Eccentric Reducer at Centrifugal Pump Inlet?",
        "text": "I am an operation and maintenance supervisor at a chemical equipment importing enterprise in Shanghai. We just imported 12 horizontal centrifugal pumps from Germany last week. The temporarily hired outsourced technician had no experience in piping installation for imported pumps, and installed the matched eccentric reducer in the wrong direction. The pump frequently produces harsh cavitation noise when starting. Worse still, when customs carried out inspection at Yangshan Port last Wednesday, the on-site engineer pointed out that the installation did not comply with the original manufacturer's specifications and required rectification before release. Now the cargo has been detained at the port for 6 days, with a daily detention fee of RMB 1200. The end customer is pressing for the acceptance certificate, and my boss also puts pressure on me every day. I am too anxious to sleep, and I would like to ask for advice: from the two core perspectives of import compliance inspection and equipment operation and maintenance, how should the eccentric reducer at centrifugal pump inlet be installed to not only pass customs inspection smoothly, but also completely avoid cavitation and other equipment failures?",
        "answerCount": 8,
        "upvoteCount": 4,
        "datePublished": "2026-07-19T21:55:57Z",
        "dateModified": "2026-07-19T22:16:44Z",
        "author": {
          "@type": "Person",
          "name": "Zhongshen Trading China",
          "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html"
        }
                ,"acceptedAnswer": {
            "@type": "Answer",
            "text": "There are three common installation mistakes in the industry: first，randomly selecting the eccentric direction and adopting "flat-bottom" installation for the eccentric reducer at the inlet of horizontal centrifugal pump，second，ignoring the levelness requirement，leading to piping deviation exceeding the equipment's allowable range，third，skipping air tightness test and starting the equipment directly after installation. These mistakes will trigger a chain of negative reactions: wrong eccentric direction will cause gas accumulation at the pump inlet，leading to serious cavitation，which will damage the impeller in as short as 3 months and directly burn the motor in severe cases，meanwhile，during on-site customs inspection，non-compliance with original manufacturer's specifications will lead to determination of inconsistent declaration，triggering customs detention and port detention. According to the 2026 detention fee standard of Shanghai Port，the daily detention fee per container can reach RMB 1200，and the detention fee for a one-week delay exceeds RMB 8000. Excessive levelness deviation will cause uneven stress on the pump shaft，trigger high-frequency vibration and damage sealing parts. For physical risk prevention，two core operations must be strictly implemented: The eccentric reducer at the inlet of horizontal centrifugal pump must adopt "flat-top" installation to avoid gas accumulation， Control the levelness deviation within 0.5mm/m ，and calibrate section by section with a high-precision level. After installation，use the soapy water leak detection method to conduct air tightness test on all piping joints to ensure no leak points. Exclusive loss mitigation tip: If installation error or customs inspection objection has occurred，immediately coordinate with the original manufacturer to issue a Chinese-English installation specification certificate，submit it to the customs for expedited re-inspection，and at the same time provide the customs inspection notice to the shipping company to apply for more than 50% reduction of detention fee，after equipment rectification，conduct a 1-hour no-load trial operation and record operating noise and vibration data as supplementary compliance proof.",
            "upvoteCount": 4,
            "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html#acceptedAnswer",
            "datePublished": "2026-07-20T00:36:54Z",
            "author": {"@type": "Person","name": "Victor Sun","url": "https://www.sh-zhongshen.com/en/team/victor-sun/"}        }
                ,"suggestedAnswer": [
                  {
            "@type": "Answer",
            "text": "The installation specification of eccentric reducer at centrifugal pump inlet is one of the core compliance bases for customs document review and inspection. If the installation parameters of the matched reducer are not included in the equipment technical specifications during declaration, or on-site installation does not match the document marking, it will directly trigger an early warning of inconsistent document and cargo, leading to problems such as declaration deletion and re-submission, valuation dispute and even customs detention. Enterprises need to translate the English installation specification provided by the original manufacturer into Chinese, affix the special customs declaration seal, and submit it to the customs as an attached document. Meanwhile, clearly mark key parameters such as "Matched eccentric reducer adopts flat-top installation, levelness deviation ≤ 0.5mm/m" in the "Specifications and Model" column of the Import Goods Declaration Form. If inspection objection has occurred, immediately coordinate with the original manufacturer to issue an installation compliance certificate, apply for expedited re-inspection by customs, and submit the detention fee reduction application at the same time to avoid additional costs caused by process delay.",
            "upvoteCount": 0,
            "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html#suggestedAnswer-2",
            "datePublished": "2026-07-20T00:27:24Z",
            "author": {"@type": "Person","name": "Evelyn Li","url": "https://www.sh-zhongshen.com/en/team/evelyn-li/"}          }
          ,          {
            "@type": "Answer",
            "text": "The installation of eccentric reducer matched with imported centrifugal pump needs to be closely connected with port logistics nodes. Improper operation during temporary installation at the port will not only cause equipment damage, but also occupy terminal storage resources and extend detention time. Enterprises need to plan the installation site in advance, give priority to bonded warehouses with equipment installation qualification for pre-installation, and avoid operation in open terminal areas. At the same time, negotiate with the shipping company to extend the free storage period. If the deadline is exceeded due to installation rectification, you can submit the inspection rectification notice issued by the customs to apply for reduction of container detention fee and port detention fee. In addition, after installation, the equipment needs to be re-fixed with shock-proof packaging to ensure that piping joints do not loosen during subsequent inland transportation.",
            "upvoteCount": 0,
            "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html#suggestedAnswer-3",
            "datePublished": "2026-07-19T23:48:05Z",
            "author": {"@type": "Person","name": "Michael Zhang","url": "https://www.sh-zhongshen.com/en/team/michael-zhang/"}          }
          ,          {
            "@type": "Answer",
            "text": "The installation cost of eccentric reducer at centrifugal pump inlet can be included in the calculation of the customs dutiable value of imported equipment, but it needs to meet compliance conditions. If the installation service is provided by an overseas manufacturer, it is necessary to clearly distinguish the equipment price and the installation service fee during declaration, to avoid overestimated dutiable value caused by combined declaration, which increases the cost of import tariff and value-added tax. Meanwhile, if the enterprise meets the applicable conditions of the 2026 VAT deferral policy of Shanghai Customs District, the value-added tax corresponding to the installation service can be included in the deferral scope to ease capital pressure. It should be noted that the certificate of installation cost needs to include detailed service content, expense breakdown and payment certificate, to ensure that a complete document chain can be provided during tax authority inspection, and avoid tax adjustment caused by missing certificates.",
            "upvoteCount": 0,
            "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html#suggestedAnswer-4",
            "datePublished": "2026-07-19T23:02:41Z",
            "author": {"@type": "Person","name": "Grace Wang","url": "https://www.sh-zhongshen.com/en/team/grace-wang/"}          }
          ,          {
            "@type": "Answer",
            "text": "The installation of eccentric reducer at centrifugal pump inlet involves compliance of cross-border foreign exchange payment and receipt. If the installation service is provided by an overseas supplier, it is necessary to clearly mark "Installation Service Fee for Centrifugal Pump Matched Eccentric Reducer" in the SWIFT message, to avoid being included in the foreign exchange regulatory warning list due to vague purpose of payment and receipt. Meanwhile, if RMB cross-border payment via CIPS is adopted, it is necessary to ensure that the payment certificate is consistent with the service content in the customs declaration and contract, so as to avoid settlement and reconciliation problems caused by mismatch between cargo right and capital flow. Enterprises need to include installation services in the subsidiary clauses of the trade contract in advance, clarify the service content, fee standard and payment nodes, to ensure that foreign exchange payment and receipt operations comply with the relevant regulations of the State Administration of Foreign Exchange.",
            "upvoteCount": 0,
            "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html#suggestedAnswer-5",
            "datePublished": "2026-07-19T22:52:59Z",
            "author": {"@type": "Person","name": "Cindy Chen","url": "https://www.sh-zhongshen.com/en/team/cindy-chen/"}          }
          ,          {
            "@type": "Answer",
            "text": "In the trade contract for imported centrifugal pumps, it is necessary to clearly define the installation specifications and acceptance standards of the eccentric reducer, so as to avoid equipment failure disputes caused by the manufacturer's failure to provide clear installation guidance. An "installation compliance umbrella clause" should be added to the contract: if equipment damage or customs inspection failure is caused by incorrect installation specifications provided by the manufacturer, the manufacturer shall bear the port detention fee, rectification fee and equipment maintenance fee. At the same time, the manufacturer should be required to issue a Letter of Indemnity (LOI) for installation compliance, which is one of the core basis for equipment acceptance. If a dispute has occurred, immediately start the verification of the force majeure clause. If the delay is caused by the manufacturer's failure to provide installation guidance in time, you can claim relevant losses from the manufacturer according to the contract.",
            "upvoteCount": 0,
            "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html#suggestedAnswer-6",
            "datePublished": "2026-07-19T22:40:32Z",
            "author": {"@type": "Person","name": "Daniel Xu","url": "https://www.sh-zhongshen.com/en/team/daniel-xu/"}          }
          ,          {
            "@type": "Answer",
            "text": "When customs inspects the installation of eccentric reducer at centrifugal pump inlet on site, it mainly checks three core indicators: eccentric direction, levelness and piping tightness. It is necessary to prepare tools such as level meter and air tightness detector in advance, and cooperate with customs engineers for on-site testing. If wrong eccentric direction installation is found (such as flat-bottom installation), it is necessary to adjust and re-fix immediately, and explain to the customs that the adjustment is based on the original manufacturer's installation specifications. If the piping is not tightly sealed, the sealing gasket needs to be replaced on site and the pressure test re-conducted to ensure that the test data meets the technical requirements of the equipment. In addition, it is necessary to sort out the original manufacturer's installation manual, test report and other materials in advance, to avoid prolonging the inspection time due to incomplete materials.",
            "upvoteCount": 0,
            "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html#suggestedAnswer-7",
            "datePublished": "2026-07-19T22:37:27Z",
            "author": {"@type": "Person","name": "Andy Guo","url": "https://www.sh-zhongshen.com/en/team/andy-guo/"}          }
          ,          {
            "@type": "Answer",
            "text": "After the installation of eccentric reducer at centrifugal pump inlet is completed, it needs to be fixed with special packaging that meets international transportation standards, to avoid loosening or damage of piping joints during subsequent transportation. The piping joints should be wrapped with high-density EVA buffer material, and the overall frame of the equipment should be reinforced with steel strips to ensure that the impact resistance of the packaging meets the ISTA 3A standard. If the equipment needs to be transported long-distance inland, warning signs such as "Fragile, Do Not Invert, Piping Installed Handle With Care" should be marked on the outside of the packaging. At the same time, the loading and unloading responsibility of the carrier should be clearly defined in the transportation contract, to avoid damage to the installed piping caused by rough handling. In addition, photo materials before and after packaging should be retained as core evidence for subsequent claims.",
            "upvoteCount": 0,
            "url": "https://www.sh-zhongshen.com/en/qa/centrifugal-pump-eccentric-reducer-installation-specifications-pitfall-prevention.html#suggestedAnswer-8",
            "datePublished": "2026-07-19T22:16:44Z",
            "author": {"@type": "Person","name": "Linda Gao","url": "https://www.sh-zhongshen.com/en/team/linda-gao/"}          }
                  ]
              }
    },
    {
      "@context": "https://schema.org",
      "@type": "BreadcrumbList",
      "itemListElement": [
          {"@type": "ListItem", "position": 1, "name": "Home", "item": "https://www.sh-zhongshen.com/en/"},{"@type": "ListItem", "position": 2, "name": "Q&A", "item": "https://www.sh-zhongshen.com/en/qa/"},{"@type": "ListItem", "position": 3, "name": "Import Agency Q&A", "item": "https://www.sh-zhongshen.com/en/qa/cat-import-agency/"}          ,{"@type": "ListItem", "position": 4, "name": "What Core Operating Specifications and Pitfall Prevention Points Should Be Followed for Installation of Eccentric Reducer at Centrifugal Pump Inlet?"}
      ]
    }
]
```