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The Silver Automation Instruments HH50 metal tube variable area flow meter is a direct mechanical replacement for the Krohne H250/RR/M40. Available in DN50 (2") with ASME B16.5 150LB flanges, SS316 wetted parts, and a 25,000 L/h range on water — priced between $700 and $1,200 USD depending on output configuration. Lead time is 7–10 working days from China.
Krohne makes excellent meters. No one disputes that. But when a Krohne H250/RR/M40 fails on a cooling tower or utility water loop, the replacement quote often comes back at $2,500–$4,000+ USD, with a 6–10 week lead time from Europe. For a DN50 rotameter measuring water with no special process hazard, that cost is hard to justify.
We see this exact situation regularly. Last month a maintenance buyer in Mexico contacted us with a Krohne SAP datasheet — Clave SAP 12047409, a caudalímetro de área variable 2" measuring 5,100–25,000 L/h on water at 20°C, installed in a cooling tower section. The question was straightforward: can you offer something equivalent?
Yes. Here is what a direct replacement looks like.
• Type: Variable area flow meter (metal tube rotameter)
Criticality level on that site: C4. Meaning it is not critical to stop the process, and it can be substituted. That is exactly the scenario where a cost-effective alternative makes sense.
The Silver Automation Instruments HH50 series is a metal tube variable area flow meter designed for exactly this kind of industrial utility service. Two configurations match the Krohne H250 spec. Lead time for both: 7–10 working days after payment. We can ship DHL or FedEx to Mexico, typical transit to Mexico City or Monterrey is 5–7 business days.
Mechanical metal tube rotameter
This is the closest like-for-like drop-in. Mechanical pointer, local indication only, no power supply needed. SS316 wetted parts, DN50 with ASME B16.5 2" 150LB RF flanges. Flow range: up to 25,000 L/h on water. Accuracy ±2.5%, IP65, working pressure ≤1.0 MPa, temperature range -20 to 120°C.
It mounts the same way as the H250: low-in, top-out, vertical. No wiring. No configuration. Bolt it in and it works.
Face-to-face dimension is 250 mm, identical to the Krohne H250 DN50. The HH50 drops straight into the existing pipe spool without any spool piece modification or re-welding.
Price: approximately $700–$900 USD EXW Nanjing.
Same Install Length: 250mm
Metal tube rotameter with transmitter
If the site wants to tie the flow signal into a DCS or PLC, Option B adds a 4-20 mA output (2-wire, 24V DC) plus an LCD display showing instant and accumulated flow. Same pipe connection, same wetted materials, same flow range. This is a genuine functional upgrade over the original Krohne H250/RR/M40, which had no analog output.
Price: approximately $900–$1,200 USD EXW Nanjing.
Variable area meters are robust and low-maintenance. No electronics, no signal conditioning, no calibration drift from electrical noise. For water, cooling water, light chemicals, and similar clean liquids in utility service, they are often the right tool.
In practice, the HH50 suits cooling tower sections, water injection lines, demineralised water systems, chemical dosing return loops, and heat exchanger monitoring. We have supplied them to water treatment plants in Southeast Asia and cooling system operators across Latin America.
But there are limits. Do not use a variable area meter on gas or steam without proper calibration data. Do not use it where viscosity exceeds roughly 300 cP without a viscosity correction. And if your process requires SIL certification or ATEX Zone 1 approval, a different product line applies — ask us about the HH50-EX or our Coriolis meters for hazardous area duty.
If you have a Krohne H250 or any other brand's variable area meter that needs replacing, send us the following and we will prepare a quotation within 24 hours:
Email: inquiry@silverinstruments.com or WhatsApp +86-18936759191. For the full HH50 specification and dimensional drawings, see our variable area flow meter catalogue.
