Porous Metal Flow Restrictors

Your Dependable Porous Metal Flow Restrictors Supplier in China

Filson porous metal flow restrictors, also known as porous metal flow limiters, are devices used to restrict the flow of a fluid, in general, a gas or a liquid. They are often used in manufacturing plants and industrial applications to fulfill the main purpose of safety.

Compared to common flow control methods, Filson’s porous metal flow restrictors bring more benefits, such as higher efficiency and longer lifetime. Also, we serve our customers with multiple flow control product designs to fit the particular system.

As one of the professional porous metal flow restrictors manufacturers and suppliers in China, Filson is improving ourselves to reach the highest level of your requirements and we promise to offer the best products to support your business.

View the following article and get an appropriate porous metal flow restrictor at Filson.

Porous Metal Flow Restrictors

High Pressure Flow Restrictor
High pressure may cause the damage of the downstream equipment and even threat the safety of operators. So Filson high pressure flow restrictor is here to help solve the problem and optimize the efficiency of final product.
Flow Restrictors for HPLC
Filson flow restrictors for HPLC ( high performance liquid chromatography ) are quality products used to control flow rate and flow velocity. They are porous body sintered of metals and alloys according to customers’ requirements.
Gas Flow Restrictor
Filson gas flow restrictor, as its name implies, is mainly applied to restrict gas flow in a specific application. The treated gas could be N2, Ar, AsH3, BF3, Cl2, NH3, PH3, SiH4, HCl and others depending on your industry.
Flow Restrictors for Gas Chromatography Detectors
Filson engineers porous metal flow restrictors for gas chromatography detectors to control the flow to the detectors. They are all made of metals and alloys to ensure the rigid structure of the end product.
Drug Delivery Flow Restrictors
Filson drug delivery flow restrictors are mainly aiming at liquid drug flow control. With careful design, Filson flow restrictors can maintain the drug flow at a stable and required rate and velocity.
Flow Restrictors for Micro Metering Valves
Filson quality flow restrictors for micro metering valves are fully made of stainless steel, titanium, nickel, hastelloy, monel and other metal materials and alloys. They are highly resistant to temperature and corrosion to suit various applications.
Replacement Mott Flow Restrictor
Filson provides replacement porous metal flow restrictors for some leading brands in the market, especially for Mott. Our replacement Mott flow restrictor has the same even exceeding quality and performance than the original one, benefitting your profits.

Why Choose Filson Porous Metal Flow Restrictors

Reliable supplier for worldwide: Filson has been concentrating on filtration for more than 20 years and gained a good reputation in the industry due to its remarkable products. For now, we have exported our porous metal flow restrictors to over 30 countries and regions, serving hundreds of customers.

Innovative spirit supporting all sorts of industries: Though Filson’s porous metal flow restrictors are powerful enough to be applied to many normal fields and industries, Filson keeps upgrading and developing our technologies and expertise to perfect the product in order to expand on its applications.

Certified material for the highest quality of the product: Filson has a stable raw material supplier in China and we choose the best and most qualified construction material for your porous metal flow restrictors. Of course, we possess a series of relevant certificates like ISO 9001, CE, FDA and produce according to the standard process steps.

Competitive price in the market: Filson supplies you with quality porous metal flow restrictors at a competitive price. The products are delivered from our factory directly after finishing, which means an ex-factory price is provided to save your overall cost.

Filson Porous Metal Flow Restrictor Catalog Cover

Outstanding Porous Metal Flow Restrictors Serving Your Application

Filson is an expert in designing and manufacturing flow control devices and cooperates with experienced engineers throughout the industry. For over 20 years, Filson is striving to handle the most difficult and critical projects and provide the excellent porous metal flow restrictors for our customers.

Porous Metal Flow Restrictor Body and Housing

When it comes to flow control, Filson porous metal flow restrictr may be your premier choice. It’s a frequently-used and economical method to deliver energy to instruments and industrial processes by pneumatic fluid power. In each of applications like analytical instrument and drug delivery system, fluid has to be controlled to achieve a particular outcome.

All Filson porous metal flow restrictors are formed using high grade metal materials or metal alloys, such as stainless steel, hastelloy, nickel, brass, aluminum and inconel. Being put through a vacuum sintering process under a specific temperature, the raw material particles are pressed and combined closely together for the robust structure, possessing huge properties as well.

The most significant performance of Filson porous metal flow restrictor is its excellent durability. Sintered of metals and alloys, these restrictors are featured by good mechanical strength and high corrosion resistance to prolong the life span. Besides, the superior temperature resistance up to 760°C allows the product to be used in a wide range of applications.

There are flow restrictors in the existing market made of thermoplastics, nylon and fluoropolymers. Regardless of price ( they are cheaper of course ), they do not have such good conductivity with heat and electricity like FIlson porous metal flow restrictors do. By comparison, sintered metal products are better in terms of both physical and chemical properties.

Two common methods of flow control used in most applications are flow orifice and porous metal flow restrictor which is the specialty of Filson. There are some differences between them and you can find out in FAQ part at the end of the article.

Filson porous metal flow restrictors are so versatile that, in some cases, they can replace the drilled orifice, capillary tubing and needle valves that wear over time. Meanwhile, they provide unexpected performance and results.

Porous Metal Flow Restrictors Packing

It’s reasonable that Filson porous metal flow restrictor is designed carefully to maintain a proper differential pressure for fluids to move. During the process, it not only controls the flow rate, but also guarantees the downstream equipment free from contaminants in the initial gases.

Something you should know about FLOW:

  1. Flow is the movement of pressurized fluids between volumes of varying ( differential ) pressures.
  2. If there is no differential pressure, the fluid will be stationary and the system is absent of flow.
  3. Pressurized fluid always moves from higher pressure to lower pressure. ( same in a Filson porous metal flow restrictor )

Porous Metal Flow Restrictor Assemblies

Another advantage that is worth mentioning is Filson porous metal flow restrictor has thousands of pores instand of one orifice allowing gas to go through, which greatly reduces the probability of blockage.

How is the flow control achieved? What are ideal products for controlling fluid? How do they influence the result? These may still be your confusions about Filson porous metal flow restrictors. However, they can be solved easily by our professional specialists, consult us today and get the desired answers.

Ways to get in touch with Filson:

Phone: 86 – 157 3695 8886


You are welcomed to discuss any technical questions and project problems with us!

Working Principle of Porous Metal Flow Restrictors

Filson Porous Metal Flow Restrictors Function:

  • Provide protection for some vital components in the system
  • Reduce exhaust system requirements and reduce cost at the meantime
  • Tailor suitable solution for each gas supply line
  • Control venting flow rate during vacuum chamber venting or purging process
  • Act as pressure snubber to avoid pressure surges and pressure shock
  • Prevent the flame from igniting a combustible gas

Filson Porous Metal Flow Restrictors Feature:

  • Improved gas safety using the effective porous metal flow restrictors
  • Accurate and repeatable flow assurance under a set pressure
  • Fixed flow or stable flow control without moving parts or adjustments
  • Quality raw material for consistent temperature and corrosion resistance
  • No gas leakage for safety and ensured seal integrity
  • Easy cleaning and installation for less downtime
  • Unifrom pore distribution leading to thousands of paths for fluids
  • Advanced anti-clog multi-pore technology for long-lasting

Filson Porous Metal Flow Restrictors Specification:

  • Construction material: 316L SS, 304 SS, titanium, hastelloy C-276, hastelloy C-22, hastelloy X, monel 400, nickel 200, inconel 600 ( other metals and alloys available upon request )
  • Standard working temperature: up to 450°C
  • Maximum operating temperature: up to 760°C ( upon specific metal and alloy )
  • Flow tolerance: +/- 7.5% ( higher accuracy available )
  • Standard downstream flow rates: 50 slpm
  • Standard working pressure: 120 psig
  • Maximum test pressure: 1500 psig
  • Connection: plain ends, pipe clamp ends, flanges, compression fittings

Note: custom options are available at Filson, consult our factory for other sizes, materials and more specifications.

Filson Porous Metal Flow Restrictors Application:

Porous Metal Flow Restrictor Applications

  • Chemical industry
  • Pharmaceutical industry
  • Semiconductor industry
  • Flow control of liquid drugs
  • Food and beverage ( like gas mixing into beverages )
  • Safety devices on anesthesia machines
  • Flow control in gas chromatographs
  • Laminar flow elements & Flow splitters
  • Calibrated leak detection
  • Replacement of needle valves and mass flow controllers

    People Also Ask

What are Porous Metal Flow Restrictors?

Porous metal flow restrictor is an ideal media mainly used to control flow, fitting applications which require flow restriction for either liquid or gas. On this account, the product can be called porous metal flow limiter or porous metal flow controller.

Porous metal flow restrictors are sintered bodies manufactured from stainless steel, hastelloy, nickel, monel and many other metals and alloys. According to your special needs, the construction material is available to be selected.

Filson gives porous metal flow restrictors uniform pore distribution to provide consistently laminar flow even in the most challenging process conditions. At the same time, thousands of flow paths effectively prevent the restrictor from clogging.

With robust structure and stable performance, porous metal flow resitrictor is found in all sorts of critical applications including anesthesia equipment, ventilators, ion propulsion systems in satellites and semiconductor FAB facilities.

Filson Porous Metal Flow Restrictors

How to Design a Porper Porous Metal Flow Restrictor?

Filson offers porous metal flow restrictors to meet virtually any special requirement. With rich experience in manufacturing and excellent quality in product, Filson provides a reliable solution for your flow control system. And before that, a careful design based on your specifications will be sent for you to check.

Here is the designing for proper porous metal flow restrictor:

  • Firstly, we know the purpose of designing and manufacturing the product — to achieve laminar flow and minimize velocity to control flow.
  • After lots of experimentation and testing, our engineers found that flow needs to be accurace and repeatable, typically within 7.5%.
  • Following the determination of accuracy, we may help you choose the suitable materials which must be compatible with your operating gas or liquid.
  • The whole porous metal flow restrictor can be customized at Filson including the housing. So you will find a hardware selection and design complying with your piping and fittings on the drawing.

The detailed specifications will be pointed out so that you can have a clear understanding of the total design. Just send your flow restrictor parameters, our technicist can show you the drawing of the device.

Warm tip:

For technical data on a specific Filson porous metal flow restrictor or to help identify the best design for your application, contact us with the following specifications:

  1. Type of gas/liquid
  2. Upstream pressure/downstream pressure
  3. Construction material
  4. Desired flow rate
  5. Fitting ( type, size, material )
Where Can I Use the Flow Restrictor?

These versatile porous metal flow restrictors can be applied to various industries, some of the applications are listed below:

  • Gas flow control in breathing apparatus
  • Flow control of liquid medicine
  • Flow control of gas chromatographs
  • Safety devices on anesthesia equipment
  • Gas mixing into beverages
  • Fuel metering in space probes
  • Replacement of needle valves and mass flow controllers

If your application is not shown above, please consult Filson to check if the product is suitable for your system.

Porous Metal Flow Restrictor Application

Why Porous Metal Over Other Materials? What are the Benefits?

In recent years, porous metal has become a trend and has been widely applied to a broad range of industrial applications. Experiencing a tightly controlled sintering process under a particular temperature, these porous metal products possess good physical and chemical properties.

Compared to other materials, porous metal wins in:

  • Uniform flow and pore size
  • Unique and various geometries
  • Better repeatability
  • Longevity
  • Good mechanical strength
  • High porosity
  • Excellent corrosion resistance and high heat tolerance
  • Fully cleanable and reusable
  • No media migration and no particle/powder drop
  • Customizable shape, accuracy, and dimension based on requirements

Exceeding in durability and performance, porous metal is the premier choice in manufacturing flow restrictors. Filson has good experience dealing with several applications which require much tigher tolerance and we have the capabilities to design something to meet the most challenging environment. Trust porous metal and trust Filson as well.

How Does a Flow Restrictor Work?

The porous metal flow restrictor is like a flow control valve that controls the volumetric rate of the liquid or gas that flows through it.

This porous metal flow restrictor is featured by numerous micron pores inside and outside the surface, providing thousands of passageways for fluids to pass. When passing through the restrictor, the velocity of the flow will be slow down, thus realizing the purpose of flow control.

Generally, the flow rate can be set and adjusted by changing the size of the pore size. The gap of the metal materials is a vital factor for this rate: the smaller the gap, the slower the flow velocity. Of course, different porosity can also make it different.

What are the Differences Between Flow Orifice and Porous Metal Flow Restrictor?

The two frequently-used methods of flow control in the existing industry and market are flow orifice and porous metal flow restrictor. Both can be used in your system to realize the purpose, but they’re still are great differences between them.

Flow Orifice V.S. Porous Metal Flow Restrictor

About Flow Orifice


  • Cost

Due to the simple manufacturing process and plain material, flow orifice is easy to form and cost lower than porous metal flow restrictors.

  • Choke flow

Flow orifices are designed with the intent of reducing the cross-section area with a plate and a laser drill is used to create a small hole for fluids to pass. The diameter of the hole will vary based on the flow rate, inlet pressure, and outlet pressure. And they can choke flow to some extent.


  • Easily clogged

Flow orifice only has one hole allowing gas and liquid to go through, when the particle is slightly large, the device is facing the risk of clogging.

  • High gas exit velocity

Think about that all gas is waiting to get out from the single hole, under the pressure push, the velocity of gas will be relatively high which may cause failure to the efficiency.

  • Standard designs only

The design of the flow orifice is fixed which means it can be made into standard designs only and may be more or less not quite suitable for your system.

About Porous Metal Flow Restrictor


  • Laminar flow

Porous metal flow restrictor forms thousands of flow paths to prevent the device from clogging if a large particle makes it into the gas stream. This unique structure is able to ensure the laminar flow in even the harshest conditions and eliminates turbulent flow on the outlet.

  • Thousands of flow paths

After a sintering process, the porous metal flow restrictor is made porous and thousand of pores are created for fluids to pass. The vast flow paths share the gas/liquid flow and limit the rate, at the same time, provide the safest pressure.

  • Customizable flows

Porous metal flow restrictors are customizable in materials, micron ratings, efficiency, connection types, and dimensions. The selection of the right device is totally up to you. And it is possible for our factory to design and tailor the desired product according to your application.


  • Cost

Because of the high production cost and raw construction material ( mainly metals and alloys ), porous metal flow restrictors usually cost more than the common flow orifice.

  • Cannot choke flow

The fluid is evenly distributed downstream through the pores so that this porous metal flow restrictor cannot choke flow.

Both of the flow control methods have their own advantages and disadvantages, you can choose the proper one after deep consideration. If you have trouble deciding which product to use, please feel free to contact Filson for help.

Flow Orifice VS Porous Metal Flow Restrictor

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