ranQ
ranQ
ranQ
DirectoryIndustriesPlacesKnowledgeComparisonsSoon
Sign inCheck visibility
ranQHSG Startup LabelRecognised by the
HSG Startup Label

The leading AI company directory, built to boost AI visibility.

DEENFRIT
Product
  • Pricing
  • Directory
  • Industries
  • Trust Score
Company
  • About
  • Partner program
  • Contact
  • Legal
© 2026 cohaga AG · All Rights Reserved · St. Gallen, Switzerland · Imprint746,818 companies indexed · Last updated: today
DirectoryBusiness & Technical ServicesEngineerBaselLasso Technik AG
Lasso Technik AG Logo
Verified· 5 sourcesOwner confirmed
Last updatedNovember 5, 2026

Contact

Summary

About the company

Lasso Technik AG is a Swiss family-owned company based in Basel, founded in 1942. Its core activity includes the development, manufacture and distribution of valves under the Stop Silent® brand. The range is divided into two product lines: The Stop Silent® SL13 check valves protect against backflow of fecal-containing wastewater and serve as a barrier against radon and sewer gases. The Stop Silent® AS backflow valves prevent backflow in drinking water and industrial facilities. Lasso Technik supplies customers at home and abroad and also develops customized solutions.

AI-generated
Presence

Service area

Offering

Products & services

Industry:Engineer
LeadhubOutbound Leads by COHAGA

Looking for direct email addresses and phone numbers?

Leadhub delivers verified contact details and decision-makers from over 750,000 Swiss companies — management, procurement, marketing, HR.

Discover Leadhub
Call
Trust Score4.6/5

Lasso Technik AG

Architect
Civil works
Civil engineer
Landscaping
Water supply
Mechanical engineering
✓ Offered2
Backwater protection (Stop Silent SL13)
Backwater protection devices for rainwater and sewage containing faeces; protection against backflow, basement flooding, sewer gases and radon, with fast installation even in oval pipes.
Non-return valves (Stop Silent AS)
Non-return valves for drinking water, industry as well as sandy, pasty and gaseous media; various designs such as AS41, AS54, ASSF, ASEA, ASMK and ASFV.
Expertise

Expert

A
Alain Perrin
Marketing

Trained machinist with commercial training. Since 2005 active in marketing, product management and technical purchasing. Since 2022 I have been Marketing Director at Lasso Technik AG.

Qualifications & certifications
Marketingplander 2005
Maschinenmechaniker1998
Trust & reputation

ranQ Trust Score of Lasso Technik AG: 4.6 out of 5.0

Trust Score4.6/ 5.0

Excellent

x

Data basis 100% · As of November 2026

Lasso Technik AG scores 83.3 out of 100 points in the Reputation area of the ranQ Trust Score. This area carries 42% of the weighting.
x
CriterionValueWeight
  • Review quality: The average rating across all connected sources, smoothed against the industry mean. So 5.0 stars from three reviews do not outrank 4.7 from three hundred.84.724%
  • Review volume: The number of reviews across all sources. The scale is logarithmic: the first reviews count the most, and the maximum is reached at 50 reviews.76.210%
  • Review recency: The age of the most recent review. Two-year-old reviews deliberately sit in the middle, because that is normal for Swiss SMEs. Only after three years without a new voice does the value drop markedly.88.08%
Lasso Technik AG scores 85.5 out of 100 points in the Substance area of the ranQ Trust Score. This area carries 28% of the weighting.
x
CriterionValueWeight
  • Establishment: Years since founding or brand launch, logarithmic. The maximum is reached at 15 years.100.012%
  • Company size: The headcount band, researched by ranQ or stated by the company. It is scored in steps rather than by head count, because the data only provides bands.55.07%
Lasso Technik AG scores 100.0 out of 100 points in the Identity area of the ranQ Trust Score. This area carries 22% of the weighting.
x
CriterionValueWeight
  • Verification: Official register entry (commercial register with UID or professional-body record, 55 points), confirmed domain (20 points) and confirmed ranQ profile (up to 25 points, depending on completeness).100.022%
Lasso Technik AG scores 53.1 out of 100 points in the Visibility area of the ranQ Trust Score. This area carries 8% of the weighting.
x
CriterionValueWeight
  • Website authority: Ahrefs' Domain Rating measures, on a scale of 0 to 100, how strongly a website is linked from other websites. For Swiss SMEs the range up to 40 is typical; the maximum is reached at 35.62.94%
  • Media authority: Quality and number of editorial mentions, weighted by the importance of the source, plus the recency of the latest high-quality mention.43.34%
Qualifications+0.15

Lasso Technik AG reaches a ranQ Trust Score of 4.6 out of 5.0 — rated «Excellent». The rating draws, among other things, on 4.9 out of 5 stars from 19 customer reviews. As of November 2026.

The Trust Score cannot be bought and is calculated from publicly verifiable data.

Reviews

Aggregated rating

Aggregated rating
4.9
of 5

Aggregated from 19 reviews across all connected sources

Sources
GGoogle4.919
★TrustpilotSoon
PProvenExpertSoon

Further sources are added continuously and factored into the ranQ Rating.

Common questions

Answers

What are Stop Silent check valves type AS used for?
Stop Silent check valves prevent media from flowing back unintentionally. They are used in drinking water, industrial, and special applications with sandy, paste-like, or gaseous media. They protect systems, processes, and pipelines. The AS-type valves have the largest functional opening on the market.
What does the Stop Silent SL13 backflow prevention protect against?
The Stop Silent SL13 protects against backflow caused by wastewater containing fecal matter from the sewer and thus helps prevent basement floods. It also protects against the intrusion of sewer gases and radon with the quickly retrofitted backflow gate. In this way, it markedly increases safety in buildings.
Can the SL13 also be mounted in oval tubes?
Yes, the backflow protection Stop Silent SL13 is designed for quick installation, even in oval tubes. This simplifies installation under different architectural conditions. This often allows for a more efficient installation.
What check valve designs does Lasso Technik AG offer?
The product range includes various designs such as AS41, AS54, ASSF, ASEA, ASMK and ASFV. Depending on the medium, installation situation and requirements for pressure loss, the appropriate solution can be selected. This simplifies the sizing for different applications.
What advantages does the patented Stop Silent® AS check valve offer?
The patented Stop Silent® AS check valve provides the largest functional opening on the market for high flow rates with low pressure loss. The elastic membrane closes smoothly and quietly, reducing water hammer and protecting lines, pumps and fittings. The design is wear-resistant. The stainless steel cone also serves as a coarse filter. Different membrane materials allow use with drinking water and industrial media. The valve can be installed horizontally or vertically and, depending on the variant, is suitable for operating pressures up to 16 bar.
Press

Media

July 23, 2026Media
Stop Silent – die Rückflussverhinderung
gebaeudetechnik.ch
July 23, 2026Media
Stop Silent – die Rückflussverhinderung:
gebaeudetechnik.ch
June 21, 2026Blog
Temporäre Wasserentnahme ab Hydranten – mit dem Rückflussverhinderer Stop Silent AS41
stopsilent.ch
May 14, 2026Media
Planer Installateur - Gummi als Funktionselement
gebaeudetechnik.ch
May 13, 2026Blog
Hochwasserschutz beim Regenüberlauf Alberti in Davos
stopsilent.ch
April 13, 2026Blog
Stop Silent Typ AS: Der Schlüssel zu makellosen Produkten im Vakuum-Mischen
stopsilent.ch
April 9, 2026Blog
Wafer Check Valve aus Edelstahl - Zwischenflansch Rückschlagventile Stop Silent AS54
stopsilent.ch
November 14, 2025Blog
Kalkulationsdaten von Suissetec - Digiales Bauen Stop Silent AS Produkte sind dabei.
stopsilent.ch
August 11, 2025Blog
3 Risiken bei Starkregen für Ihr Haus
stopsilent.ch
September 16, 2024Blog
Radon - Krebsursache Nr. 2 – nach dem Tabak - Sich vor Radon im Gebäude schützen:
stopsilent.ch
September 12, 2024Blog
Schweizer Baumuster-Centrale Zürich - Anschauen - Anfassen - Ausleihen
stopsilent.ch
September 9, 2024Blog
CRB Ausschreibungtext - Standards für das Bauwesen
stopsilent.ch
September 9, 2024Media
Überflutung des Untergeschosses: Was kann man vorbeugend tun?
der-hauseigentuemer.ch
Blog
Funktionsweise der AS-Kegelmembrane
stopsilent.ch
Credentials

Certifications & memberships

Suisstec Mitglied
Branchenverband für die Gebäudetechnik
VSA
Verband Schweizer Abwasser- und Gewässerschutzfach
SVGW
Trinkwasserteitifikat
Knowledge

Articles about Lasso Technik AG

2 articles
4 min read

How does Radon prevention protect the building?

At Lasso Technik AG we do not see the topic as theory but as part of a functioning protection concept in construction. Especially where pipes, floor drains or duct shafts create weak points, the combination of construction sealing and technical backflow protection is decisive.

October 1, 2026·Read article
Comparisons

Lasso Technik AG in comparison

Soon

Industry comparisons are coming soon

We're preparing industry comparisons that rank Lasso Technik AG by reviews, experience and specialisations.

Contact

Location

Niklaus von Flüe-Strasse 33
4059 Basel
Opening hours
Mon
08:00 - 17:00
Tue
08:00 - 17:00
Wed
08:00 - 17:00
Thu
08:00 - 17:00
Fri
08:00 - 17:00
Sat
Closed
Sun
Closed

At a glance

Legal form
Corporation
UID
CHE-105.923.119
Founded
1942 · 84 years
Last commercial register change
December 3, 2021
Employees
1 to 10

Active in 25 of 26 cantons

  • AGAargau
  • AIAppenzell Inner Rhodes
  • ARAppenzell Outer Rhodes
  • BLBasel-Country
  • BEBern
  • FRFribourg
  • GEGeneva
  • GLGlarus
  • GRGrisons
  • JUJura
  • LULucerne
  • NENeuchâtel
  • NWNidwalden
  • OWObwalden
  • SHSchaffhausen
  • SZSchwyz
  • SOSolothurn
  • SGSt. Gallen
  • TGThurgau
  • TITicino
  • URUri
  • VSValais
  • VDVaud
  • ZGZug
  • ZHZurich
Legal form: Graded by liability and disclosure. The weight is kept small: a sole proprietorship is not a dubious company, it is just liable differently.
100.0
6%
  • Branch offices: Branch offices linked in the commercial register. Having none is normal and costs no points.70.03%
    • 4 min read

    How does a Wafer Check Valve save space and costs?

    At Lasso Technik AG we do not view the wafer check valve as a niche solution, but as a practical answer to tight installation situations. Especially where space, maintenance access and operational safety converge, the wafer design shows its strengths.

    September 17, 2026·Read article
    Full methodology