Space Simulation and Thermal Vacuum Systems

We manufacture a complete line of Thermal Vacuum Chambers, Space Simulation Systems, and Ultra High Vacuum Testing Facilities.

From the very first orbital simulator manufactured in the United States in the 1950’s, to state of the art turbo mechanical, cryogenic, and ion pumped systems, we offer all embracing capability and technical expertise in this specialized field.

We design and manufacture our own vacuum vessels, we manufacture our own thermal shrouds from “Bemcoil,” an exclusive Bemco product, we manufacture our own base plates and heat exchangers, we manufacture our own fluid and gas circulating systems, and we use only the most reliable, carefully tested components.

This page serves as the master index page for our Space Simulation and Thermal Vacuum System products. Clicking where indicated will take you to the sub-page that describes additional products, contains tables comparing choices, or has technical details. You can return to this page by clicking on the "Return Arrow" at the bottom of each sub-page.

---

Construction

Every Bemco thermal vacuum or high vacuum chamber can be furnished in a round or a square workspace shape. The smallest available systems start at 12 inches inside diameter or 12 x 12 inches wide and high by any length and increase to the largest machines with measurements of 50 feet inside diameter or 50 feet wide and high by any length. The largest systems must be constructed, at least partially, on site due to shipping restrictions.

Bemco chambers and all vacuum accessories, including access ports, are reinforced in accordance with, and designed to meet, Section VIII of the ASME Code (Unfired Pressure Vessels). No code stamp is applied since pressures are less than 15 psid. Chambers are available with inner surfaces made from high strength steel, 304 Series stainless steel, and 316 series stainless steel. For normal high vacuum service, 304 Series stainless steel is recommended. Carbon steel is sometimes specified for very large vessels where cost is a primary consideration and 316 series stainless steel is suggested for pharmaceutical applications and clean rooms.

All chambers include a replaceable “O” ring seal. Interior chamber surfaces are ground smooth and polished for low emissivity and to minimize outgassing. All Bemco high vacuum chambers are tested with a helium mass spectrometer sensitive to 1 x 10 -9 Torr.

Supporting Structure

Exterior chamber reinforcement, enclosures, and structures, with the exception of the door sealing face which always matches the interior material, are made from high strength steel and carbon steel finished with a preventative primer and a Bemco Blue overcoat. Custom colors are available on request. All components used on Bemco Thermal Vacuum and Space Simulation Systems are high vacuum rated.

Fluid and Gas Thermal Conditioners

Liquid nitrogen, circulated fluid, and circulated gaseous nitrogen conditioning of shrouds and base plates are offered. Each system has its own advantages. Flooded and circulated liquid nitrogen systems are selected for continuous operation at -185 C (-300 F).

Gaseous nitrogen conditioners are chosen for their wide operating temperature range and are also specified when the unusual possibility of circulating fluid leakage in the workspace outweighs the gaseous system’s much higher first cost. Gaseous conditioners require high pressure, larger horsepower blowers, custom heat exchangers, and special low pressure drop gas circuited headers on the associated thermal shrouds and baseplates.

Circulating fluid systems are the most common type selected. They offer the advantages of excellent thermal uniformity under load and relatively lower operating cost.

Bemco PCL-III fluid conditioners are furnished as free standing caster mounted systems, ready to provide a reliable and precisely controlled flow of temperature conditioned fluid. To save floor space, these systems are also packaged with larger space simulators and thermal vacuum systems. Bemco’s A6H Standard Space Simulators, described on a separate page on this web site, each include a fully integrated and appropriately sized PCL-III fluid conditioner.

You can see more information on our PCL-III Fluid Conditioners by clicking on the "PCL" graphic or you can download our AH Bulletin or our PCL Bulletin, where more information is available including a recommended circulating fluids list. For the PCL-III, the temperature ranges shown in the above range chart do not apply to all fluids. In some cases, the total temperature range of a given conditioner is limited by the temperature capabilities of the circulating fluid.

Bemco HPG, High Pressure Gas Conditioners, while available as free standing units, are usually directly integrated with a thermal vacuum system or space simulator to provide a high pressure circulating source of temperature conditioned gaseous nitrogen flowing inside a thermal shroud or baseplate.

HPG Conditioners are similar to our PTS Portable Temperature Conditioners except they are designed for continuous operation at up to two atmospheres (29.4 psia) of pressure. This higher base operating pressure doubles the gas density per cfm of circulating gaseous nitrogen allowing the use of smaller connecting tubes while also increasing thermal capability. You can see more information on our HPG Gas Conditioners by clicking on the "HPG" graphic.

Nitrogen is the typically selected circulating gas. In the unusual event of an internal leak inside the workspace, nitrogen will normally not damage an expensive test item or cause costly interruptions in your test schedule. Because nitrogen is less dense than the fluids used with a PCL-III Fluid Chiller System, HPG conditioners can not handle as large a thermal load per unit area. Bemco's Applications Engineers can help you optimize your test load arrangement versus the chosen shroud and conditioning system.

---

Bemcoil Shrouds and Baseplates

Bemcoil, is a proprietary Bemco stainless steel shroud material proven in high vacuum service for over 50 years. This material is available in both single and double embossed versions. It is made from 18 gauge roll welded stainless steel with welded edges.

Because each panel is made to order, circuiting can be optimized to match both the fluid in the shroud and the shape of the enclosing space. Starting with shrouds as small as 12 inches in diameter, Bemcoil is available for installation in systems as large as 50 feet in diameter. You can see more information on our Bemcoil Shrouds by clicking on the "BE" graphic or you can download our AH Bulletin, where more information is available.

Bemcoil is pressure expanded in a controlling die. Unlike many aluminum shrouds that depend on conduction for heat transfer, Bemcoil has over 95% of its surface in contact with the circulating fluid. Even through stainless steel is typically not a good conductor, users report outstanding temperature uniformity due to Bemcoil’s high wetted surface-to-fluid ratio.

Stainless steel’s great advantage versus aluminum is its resistance to strain cracking and porosity induced by thermal expansion and contraction. Many users prefer Bemcoil to any other type of thermal shroud.

---

Vacuum Pumping Choices

Bemco offers a large number of choices for High Vacuum Pumping and for Roughing Pump Systems. For high vacuum pumping these choices include helium cryopumps, turbomolecular pumps, ion pumps, sublimation pumps, and oil diffusion pumps. For roughing pump systems there are rotary piston pumps, scroll pumps, Rootes booster packages, and rotary vane pumps.

All of these systems are described on the "Vacuum Pumping Systems" page on this site, click here or the image at left to go to this page, or can download our AH Bulletin, where more information is available.

---

Standard A6H Space Simulators

Bemco offers a line of up-to-date space simulators incorporating all of the preferred features needed for reliable combined temperature and high vacuum testing. The A6H series is designed in accordance with the ASME code.

These systems include a fully integrated and appropriately sized PCL-III Portable Liquid Chiller utilizing liquid nitrogen for cooling. Mechanical cooling is also available as an option.

You can see more information on our A6H Space Simulators by clicking on the "A6H" graphic or you can download our AH Bulletin.

All of these standard systems can be modified with different types of Pumping Systems, Fluid or Gas Conditioners, or accessories. A partial list of some the possible modifications is shown on the A6H page.

---

High Vacuum Components

Bemco manufactures a large number of components optimized for high vacuum use. We have a fully equipped machine shop and sheet metal shop on site, we have welding capability for a number of metals, and we have many long term supporting relationships with qualified subcontractors. In many cases these components are not shown in our catalogues since they are subassemblies of our commonly provided systems.

Our general policy is, if we can buy a standard product from a vendor that is better (form, fit, function, reliability, and both first and long term cost) than we can make, we normally do so. On the other hand, when our product is best then we make our own. This policy applies to all of our products and specifically for high vacuum components to access ports, flanges, poppet valves, traps, baffles, and and fittings.

As a courtesy to our customers we are happy to sell these components for use on a Bemco existing system, as upgrades on competitors products, or as subsystem for new facilities.

Charts outlining the technical characteristics of our PV series of stainless steel right angle poppet valves and our MCT series of cold traps can be viewed by clicking on the appropriate symbol at the left. If you have a component problem you would like solved, we would like to hear from you. Chances are, we have a solution.

---

Available Literature Includes:

Bemco AH Series Space Simulation, Ultra High Vacuum, and Thermal Vacuum Systems. Coverage includes PCL-III Portable Liquid Chillers for cooling vacuum thermal shrouds, Bemcoil DE (double embossed stainless steel) Shrouds, Bemcoil FOS (flat one side) stainless steel shrouds and Bemco PV and MCT Poppet Valves and Traps. Document is 12 pages, 1,003 KB download.

---

The systems described above are our Standard Models. We make custom equipment to your specifications.  If you have any questions, need assistance in preparing a specification, or have a technical problem you want help with, we are ready. Our quotations and advice are free.