SIHI vacuum pumps: independent brand profile
SIHI is the German pump brand behind countless liquid ring vacuum pumps in chemical and pharmaceutical plants. The name is short for Siemen & Hinsch, the two founders. Flowserve has owned it since 2015. This profile lays out the facts from Flowserve’s brand page and shows one AI assistant inventing a completely different history.
Independent profile by Vacuum Engineering Tools. We are not affiliated with SIHI, receive no payment and do not sell pumps. Quotes are the opinions of individual users, not statements of fact by us. Brand names belong to their respective owners.
In short
SIHI was founded in Germany in 1920 as Siemen & Hinsch by Otto Siemen and Johannes Hinsch, inventors of the self-priming side channel pump for liquids and gases. The company went on to develop multistage centrifugal pumps, liquid ring vacuum pumps, combi pumps, magnetic drives and dry-running vacuum pumps. Flowserve acquired the brand in 2015 and uses it for liquid pumps, vacuum pumps and engineered systems for the chemical, pharmaceutical, food, energy and water industries. There is no public owner discussion of SIHI on Reddit or the forums we checked.
Verified facts
What users say
A search of Google’s index of reddit.com for SIHI pumps returned only spam shop pages that reuse the brand name. There is no Reddit discussion of SIHI pumps.
Reddit blocks automated access, so thread titles, links and previews come from Google’s index of reddit.com (October 2026). Previews are excerpts, not the full comment.
From specialist forums
SIHI pumps are specified by chemical and process engineers and are discussed in engineering terms (sealing liquid, cavitation, capacity) rather than by brand in public forums.
No quotable forum posts found.
AI fact-check: what ChatGPT, Gemini, Perplexity and Claude say
On 9 October 2026 we asked all four assistants the same question (who owns SIHI, headquarters, founding, best-known series and what buyers say) and checked every answer against the manufacturer’s own pages.
| Question | ChatGPT (gpt-5.5) | Gemini (3.5 Flash) | Perplexity (Sonar) | Claude (Sonnet 5.5) | Verified |
|---|---|---|---|---|---|
| Who owns it? | ✓ Flowserve | ✓ Flowserve | ✓ Flowserve, since 2015 | ✗ “Sulzer; vacuum line sold to Ebara” | Flowserve, since 2015 [Source] |
| Headquarters | ~ Irving, Texas (Flowserve HQ) | ? Itzehoe, Germany | ? Grand Island, New York | ? Itzehoe, Germany | Not stated on Flowserve’s SIHI page [Source] |
| Founded | ✓ 1920, Otto Siemen & Johannes Hinsch | ✓ 1920, Otto Siemen & Johannes Hinsch | ✓ 1920, Otto Siemen & Johannes Hinsch | ✗ “1906”, Siemen & Hinsch | 1920, Otto Siemen and Johannes Hinsch [Source] |
| Series named | ✓ LPH, LEM, KPH | ~ LPH, dry_run, SIHIgass | ✓ LPH-X, SIHI Dry, SIHI boost | ✓ LPH, LEM, LPA/LEL | LPH/LPHX and LEM liquid ring lines plus dry-running pumps [Source] |
✓ correct · ~ partly right or outdated · ✗ wrong · ? cannot be checked against an official source. Answers condensed. Only Perplexity used web search; the other models answered from training data.
Three assistants matched Flowserve’s page exactly: founded 1920 by Otto Siemen and Johannes Hinsch, owned by Flowserve since 2015. Claude wrote a different history altogether: Sulzer as owner, the vacuum line sold to Ebara, founded 1906. To its credit, it flagged ownership as uncertain, but every specific claim was wrong.
Search interest compared
Google Trends data compared with other process vacuum brands (liquid ring, ejectors, rotary piston), web search, October 2021 to October 2026. “sihi pump” has a modest share overall but leads this group in Malaysia and Indonesia and is strong in Thailand and South Korea, where chemical and process plants are expanding.
Average search interest 2021–2026 (index)
Where people search for SIHI
How to read this: of every 100 Google searches for these five brand names in Malaysia, 56 were for SIHI, more than for any other brand. It shows relative interest, not sales or market share.
| Country | SIHI share | Rank | Most searched |
|---|---|---|---|
| Malaysia | 56 % | 1st of 5 | — |
| Indonesia | 51 % | 1st of 5 | — |
| Thailand | 45 % | 1st of 5 | — |
| United States | 27 % | 2nd of 5 | Nash (31 %) |
| Sweden | 23 % | 2nd of 5 | Robuschi (61 %) |
| India | 22 % | 3rd of 5 | Robuschi (48 %) |
| Netherlands | 20 % | 2nd of 5 | Robuschi (68 %) |
| United Kingdom | 18 % | 2nd of 5 | Robuschi (75 %) |
| Mexico | 17 % | 2nd of 5 | Robuschi (60 %) |
| Australia | 13 % | 2nd of 5 | Robuschi (74 %) |
| Germany | 10 % | 2nd of 5 | Robuschi (84 %) |
| France | 4 % | 2nd of 5 | Robuschi (96 %) |
Pulled on 9 October 2026 via DataForSEO. Terms compared: “nash vacuum pump”, “robuschi”, “sihi pump”, “graham ejector”, “kinney vacuum pump”. Relative values, not absolute search volumes; non-English searches are not included.
Technology fingerprint
Computed from our directory of 25 manufacturers: which technologies SIHI offers and how common each is in the market.
| Technology | Makers in our directory | |
|---|---|---|
| Liquid ring | 9 of 25 |
Not in the range: Rotary vane, Screw, Claw, Scroll, Roots, Turbomolecular, Diaphragm
Closest alternatives
Manufacturers with the largest overlap in pump technologies.
Product series at a glance
| Series | Technology | What it is for |
|---|---|---|
| LPH / LPHX | Liquid ring | Liquid ring vacuum pumps for chemical and pharmaceutical processes. |
| LEM | Liquid ring | Compact monobloc liquid ring vacuum pumps. |
Typical fit
- Chemical and pharmaceutical process vacuum
- Solvent recovery and distillation
- Food and beverage processing
- Energy generation and municipal water
Useful calculators
Official owner resources
Find service for SIHI
Manufacturer service and independent shops in the US.
Vacuum Pump Service Directory (US) →
Frequently asked questions
Who owns SIHI pumps?
Flowserve has owned the SIHI brand since 2015 and uses it for liquid pumps, vacuum pumps and engineered systems for the process industries.
What does SIHI stand for?
Siemen & Hinsch. The company was founded in Germany in 1920 by Otto Siemen and Johannes Hinsch, the inventors of the self-priming side channel pump.
What are SIHI vacuum pumps used for?
Mainly liquid ring vacuum pumps for chemical and pharmaceutical processes, solvent recovery, food processing and power generation, plus dry-running vacuum pumps where no sealing liquid is wanted.
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