Attachment 1 - Specifications for Helium Recovery System.pdf

Attachment 1 – Requirement and Specifications for Helium Recovery, Compression, Purification, Liquefaction System

1. Background

The NIST Center for Neutron Research (NCNR) owns and operates a nuclear test reactor. The purpose of this reactor is to provide neutron radiation that can be used to study the behavior of materials under a variety of thermodynamic conditions.

During a certain class of experiments, liquid helium is used to cool experimental environments for the study of Condensed Matter Physics. Some of the helium cooling is performed by direct cooling in a cryostat in which a sample is exposed to the temperature of liquid helium (4.2 K). In such a setup, even further cooling can be achieved by evacuating the helium vapor, which reduces the liquid helium temperature even further.

These cooling techniques are based on liquid helium being consumed such that it undergoes a phase transition from liquid to gas, which is then exhausted, while in the process cooling down the equipment and eventually the sample under study.

Irrespective of whether it is in liquid or gaseous form, helium is a non‐renewable commodity, which is expected to suffer instabilities in both price and availability for the immediate and foreseeable future. These effects are due to market forces that are currently beyond the control of the U.S. Government, of which the NCNR is a part.

2. Overview of Envisioned System for NIST Center for Neutron Research (NCNR)

This specification is intended to define a requirement for a system for the Recovery, Compression, Purification, and Liquefaction (RCPL) of helium. The required system has a net production capacity of 200 liters of liquid helium per day (24 hours) and must be designed to be expandable (in terms of physical size, capacity, size and extent of the recovery manifold, etcetera). The liquefied helium is distributed through the NCNR laboratories by distributing it in transport dewars to the desired location of consumption. Here we describe a birds‐eye view of the principle of the helium RCPL system.

All helium that boils off (or is pumped from) equipment that contains liquid helium at any given time (cryostats, fixed dewars and transport dewars when stationary) is recovered. Upon recovery, the helium boil‐off enters a manifold system (i.e. plumbing) through a user interface.

The user interface includes heaters to warm up the cold gas, such as to prevent condensation of water onto the manifold system. The geometrical complexity of the manifold system is a direct function of the layout and functionality of the NCNR laboratories (see Attachment 2 – Beam overlay stations and Plumbing Layout, Power Point drawing).

The manifold system is used to carry the boil‐off to a central location under the (minimal) pressure that is developed by the boil‐off (or vacuum pump exhaust pressure). The recovered helium might pick up contaminants prior and/or during this step, notably air, nitrogen and water vapor, which must be removed prior to liquefaction. The "central location" houses all the equipment to process the helium from a recovered, somewhat contaminated gas to liquefaction.

The helium is collected in a large bladder or other gas holders, which maintains a minimal back pressure on the manifold system. The backpressure is much less than the pressure developed by the boil‐off pressure created by the various sources of recovered helium. This bladder or other gas holder is properly protected against the consequences of overpressure and exposure to other mechanical hazards. The bladder “lives” in a cage, netting, or other structure that provides appropriate support and protection.

When the bladder approaches a certain volume, the helium is removed from it and presented to the input of one or more compressors and temporarily stored in high‐pressure gas containers. This cycle is repeated for as long as helium gas flows through the manifold into the bladder.

The compressed helium is directed to a helium purifier at an appropriate pressure. There are several approaches to purification. One involves the use of liquid Nitrogen, a second approach makes use of a cold head, that in turn is driven by a closed‐cycle refrigerator. There are probably other methods to achieve this.

The purified helium is liquified and stored in a “mother dewar” that is part of the liquefaction apparatus. The typical capacity of the mother dewar no less than 500 liters.

Once a particular quantity of liquid helium (approaching the capacity of the mother dewar) is produced, liquid helium is transferred to two(2) 250 liter daughter dewars that are located at a convenient location from the point of view of both the distribution of liquified helium to the experiments and proximity to the liquefaction plant. For this transfer, one of two evacuated and permanently installed, helium transfer lines (so called “Vacuum Jacketed” or “VJ” lines) is used (the second line is an installed spare and is identical to the first one). The process of consecutive filling is automated using the process computer (i.e. a Programmable Logic

Controller, or PLC) and cryogenic valves. This automated procedure is properly informed by the helium level in the mother dewar and the levels in the daughter dewars, so that sensible liquid helium transfers take place. Any algorithm to that effect is designed to minimize the amount of liquid helium that is lost by repeatedly cooling down the VJ lines.

Regardless, some predictable losses due to cooling down the transfer line will remain. These losses can be calculated and anticipated and are added to the capacity of the helium liquefaction system (in addition to the actual requirements stated in the next sections).

Once sufficient inventory is present in the daughter dewars, a series of 100 liter liquid helium transport dewars are filled from the 250 liter daughter dewars. This is a manual process using normal laboratory grade liquid helium transfer lines. After this step the normal logistics of running the experimental facilities of the NCNR will dictate how and when the liquid helium is distributed using the 100 liter dewars.

The following performance specification aims to define the extremes of the normal range of helium usage logistics and defines how the Government intends to address it.

3. Top level Performance Specification

3.1. The helium recovery system must be able to receive, compress and store helium gas at a rate of no less than 150 liters of Liquid Helium Equivalent (LLHE) per hour, for a period of no less than eight consecutive hours (150 LLHE = 112,500 liter helium gas per hour at Standard Temperature (0 degrees C) and Pressure (10^5 Pa) (STP)).

3.2. All equipment (compressors, purifiers, liquifiers, heaters etc) must be designed and built for 24/7 continuity of operation at full power.

3.3. During a peak operational day, which can be expected to occur at least once per month, the system must be able to receive, compress and store helium gas at a rate of no less than 1500 LLHE per 24 hours.

3.4. Compressed helium must be kept in a gas storage battery of sufficient capacity (i.e.

pressure and volume), so that it can store 2000 liters of LLHE. This number is equal to the largest anticipated helium inventory at the NCNR.

3.5. The system must be capable of liquefying collected helium gas at a rate of 200 liters of liquid helium per day (one day is 24 hours). This amount does not include any helium boil‐off due to the system’s infrastructural performance needs, such as pre‐ cooling of permanently installed liquid helium delivery lines, which has to be added to the capacity.

3.6. The liquefaction system must be equipped with a no less than 500 liter “mother dewar”, located in the same room as the liquefaction system (Room F100 as identified in Attachment 2 – Beam overlay stations and Plumbing Layout, Power Point drawing, Reference 10.1).

3.7. Two 250 liter dewars (to be provided by the vendor) to be called “daughter dewars” must be located inside building G100 (location identified in accompanying documents). The daughter dewars can be consecutively filled through one low‐loss – independently evacuated – stainless steel Vacuum Jacketed (VJ) helium transfer line, that transfers liquid helium from the mother dewar in F100. A fully functional second VJ line must be present as an installed spare, that can be made functional without significant interruption of the liquid helium logistic described herein. The VJ helium transfer lines perform the same function as a regular low‐loss helium transfer line that is used when liquid helium is transferred from one container to another, with the understanding that the VJ lines specified here are permanently attached to and routed along applicable NCNR building walls (and are therefore much longer).

Anticipated liquid helium losses due to the use of these permanently installed VJ lines must be added to the gross liquefaction capacity of the system assuming one precool of one line from room temperature per day. A detailed specification for two(2) 250 L daughter dewars is included in section 8 at the end of this document.

3.8. If both VJ lines fail, it must remain possible to continue to transport liquid helium to the laboratories by transferring directly from the mother dewar to the transport dewars. It may be assumed that this will require rolling 100 liter helium transport dewars to and from the building in which the liquefaction takes place (F100).

3.9. The vacuum in the VJ lines must be maintained by suitable vendor provided vacuum pumps that interface with the VJ lines using KF‐25 ports. Each VJ line has its own vacuum port. Both ports must be are accessible from G100.

3.10. The distance from the mother dewar to the daughter dewars is estimated to be approximately 200 feet, which includes flexible low loss VJ “pigtails” to engage the mother dewar and both daughter dewars. The pigtails at the daughter dewars must be equipped with automatic cryogenic shutoff valves. The dimensions of the inside

VJ lines must be optimized to allow smooth flow of liquid helium. A basis for the helium loss due to the cool down of a VJ line is about 1 liter of liquid helium per kilogram of evacuated transfer line (i.e. only the weight of the inner tube of the VJ assemblies), so it is advantageous to design the inner tubes as thin as possible. The validity of this design basis must be verified by the vendor before he/she specifies the liquefaction capacity of the system.

3.11. The driving pressure for the 500 liter mother dewars and the two 250 liter daughter dewars must be provided by an appropriate electric heater incorporated in the dewars. The mother dewar heater must be operated through a central computer, so that the liquid helium transfer from the mother dewar to daughter dewars can be done automatically and intelligently, with the aim to minimize helium losses. The daughter dewar heaters must be operated manually. There must be a provision for all helium boil‐off for VJ line precooling to be automatically collected back to the helium recovery system. This system must be designed such that no warm helium gas that has been warmed up by cooling down the VJ line is ever admitted into a daughter dewar.

3.12. A liquid helium transfer/fill station must be located at the area designated on the layout schematic provided by the NCNR (See Attachment 2 – Beam overlay stations and

Plumbing Layout, Power Point drawing). This is in the same area that houses the daughter dewars and is intended to transfer liquid helium from the daughter dewars to the transport dewars.

3.13. The transfer/fill station must be equipped with two scales for weighing 100 liter transport dewars. These scales are located next to the daughter dewars. These scales must have 0.1 lbs accuracy and have sufficient range to properly detect the liquid level in the transport dewars. Scales must have digital readouts. Scales must be equipped with ramps for rolling transport dewars on and off.

3.14. The purity of liquified helium must be equal or better than 99.9999%.

3.15. The system must be modular to allow future expansions in terms of rate and volume of compressed helium gas storage, liquid helium production, maximum helium boil off rate, having the ability to add more end‐user stations, as well as software expandability.

3.16. Notwithstanding user errors, the helium recovery efficiency must be no less than

95%. Recovery efficiency is defined as the ratio of the volume of liquid helium (in gas equivalent) produced and stored in the daughter dewars divided by helium gas volume collected in gas storage. This quotient maybe averaged over some considerable amount of time (such as several days, up to a week).

3.17. All gas carrying parts and joints in the gas handling system between the outlet of the purification unit(s) and the inlet to the liquefaction unit as well as inside the helium liquefaction unit(s) itself (themselves) must be sufficiently leak tight to avoid internal contamination of the liquefaction plant with environmental gasses (air, nitrogen, and water vapor) through cryopumping, which would risk making the liquefaction unit(s) inoperable through the deposition of solidified gas. In general, National Pipe

Thread connections (NPT) must be avoided.

4. Helium Monitor Stations

4.1. Nine(9) Helium Monitor Stations (HMSs) must be located at the approximate areas designated on the layout schematic attached to this specification (See Attachment 2 –

Beam overlay stations and Plumbing Layout, Power Point drawing).

4.2. The HMSs are divided over the NCNR facility as follows: one(1) in F100, one(1) in

C100, and seven(7) in G100.

4.3. Each HMS must be defined by the following features (refer to Appendix 11.1 for the functional layout the HMSs):

4.3.1. Main manual ball valve between the main manifold (“backbone”) and each branch line. The function of this valve is to shut off a branch line during trouble shooting or other maintenance.

4.3.2. Flow meter with transmitter (local indication on flow meter is not required) that is connected to the central control PLC.

4.3.2.1. Measurement range 0 – 3,750 SLPM helium.

4.3.2.2. Accuracy: better than 5% of the scale specified here.

4.3.2.3. Flow meter may be either a mass or a volume flow meter

4.3.2.4. Compatible with Tri‐Clamp Sanitary Tubing (or can be modified to be made compatible to the same)

4.3.2.5. Ability to sense the direction of the helium flow is desired, but not required.

4.3.3. Helium purity meter with transmitter (local indication on helium purity meter is not required) connected to the central control PLC. This purity meter must be able to detect impurities with a precision of 0.5%. Helium purity meter must be easy to replace. Helium purity meter principle must be based on indirect measurement of the concentration of gasses other than helium itself, because the pollutants maybe constituted of a nitrogen and oxygen mixture of unknow composition.

4.3.4. Three‐way solenoid valve, PLC controlled by helium purity meter (through the control PLC). Function of three‐way solenoid valve is to prevent contaminated helium from entering the backbone of the main manifold. The valve has the following specifications:

4.3.4.1. Position 1: valve allows clean helium gas to flow from collecting points to the backbone of the main manifold. Clean helium is defined as He fraction > X%. This value can be controlled by the system operator. The valve path to the vent is closed.

4.3.4.2. Position 2: valve allows contaminated helium gas to flow from collecting points directly to the room. The valve path to the backbone of the main manifold is closed.

4.3.4.3. The system operator can control the definition of clean helium via the PLC as follows: 80% < X < 100%

4.3.4.4. The unpowered position of the solenoid valve must be position 2

4.3.5. The threshold of the helium purity sensor measurement must be averaged over time (the averaging time must be controllable by the operator from 0 to

30 minutes).

4.3.6. All active components must be routed through the control PLC and operable from the same.

4.3.7. The HMS system must be optimized for ease of maintenance, such as replacement of constituent components.

4.3.8. The weight and dimensions of an HMS must be minimized (subject to the design and review process that is laid out in the SOW).

5. End‐user stations

5.1. End‐user stations (EUSs) must be located at the areas designated on the layout schematic attached to this specification (See Attachment – Beam overlay stations and

Plumbing Layout, Power Point drawing). There are 33 end‐user stations total (see

Appendix 0), including 6 future stations with only a capped port available on the branch manifold (i.e. no station itself).

5.2. The end‐user stations must be designed and built according to the schematic attached in Appendix 11.1, using parts compatible with helium gas usage. The internal plumbing size (including that of all its components) for the end‐user stations must be commensurate with the requirement that the pressure drop over the end user station does not exceed 1 psi at 100 LLHE per hour, which is the maximum helium flow any given end‐user station will digest. For predictive calculations, the helium temperature prior to entering the heater can be assumed to be 173 K, while the helium exiting the heater must be assumed to be 293 K. The end user station is built from a combination of compression tube fittings and Tri‐Clamp Sanitary tubing

(or equivalent). The plumbing material and other construction materials must be non‐magnetic (for example: Aluminum for framing, 316L Stainless Steel for plumbing).

5.3. Each end‐user station must be defined by the following features (refer to attached schematics in Appendix 11.1 for the end‐user stations):

5.3.1. In‐line check valve (cracking pressure 1” of Water Column and appropriate plumbing interface) to prevent helium backflow (= helium loss) into open air from the branch manifold through an accidentally left open port on the end‐ user station.

5.3.2. Manual ¼” ball valve in parallel with check valve to facilitate backflow during branch manifold refill after maintenance.

5.3.3. Pressure relief valve: 3 psi. The pressure relief valve in the end‐user station would be needed if the helium driver is a vacuum pump and an unfavorable valve line‐up within the end user station is encountered.

5.3.4. In‐line electrical heater with controller to protect downstream plumbing from the formation of condensate and ice. The heater also protects the HMS components (helium purity meter and solenoid valve) from exposure to extremely cold temperatures. It is estimated that a 2500 W heater has sufficient capacity to appropriately heat up the maximum anticipated cold helium flow for a single end user station. Basis: if helium is leaving cryogenic equipment at a rate of 100 LLHE per hour at a temperature of 173K and needs to be heated to 288K (15 degrees C). The 173K value for the helium leaving a cryostat that is consuming 100 liter of helium per hour has been experimentally determined at the NCNR by NCNR personnel. Heater must be controlled by a stand alone intelligent controller and be equipped with safety features preventing it from overheating. The heater control system must generate an audible alarm and alarm light indication upon heating system failure. Heating system failures must be analyzed for occurrence in both the heater itself (e.g. over or under heating) as well as in the control system (e.g.

solid state relay failure).

5.3.5. Analog pressure gauge: –30 Hg/15 psi, plumbed, so that is does not suffer from extremely low helium gas temperatures (as low as 173K).

5.3.6. N (variable number) manual ball valves 1” FNPT that connect to user source of recoverable helium (at an instrument station (C100 and G100): N=4; at SE prep station in the High Bay (B128): N=8; at the G100 the filling station:

N=24). See accompanying documentation for further definition of “N”;

5.3.7. All plumbing and construction materials for the End User Station must be non‐magnetic (316L, Aluminum, etc.).

5.3.8. Heater/controller circuit must be grounded and powered by a regular grounded 240V/20A plugin circuit (NEMA L6‐20 receptacles are provided by

Government).

5.3.9. The heater/controller unit must be powered by a 12 foot power cord that is fitted with a NEMA L6‐20 plug.

5.3.10. End‐user stations for which N = 4 must be designed such that they would fit equally well onto a movable platform (with casters) as to a vertical (shielding) wall. Any movable carts must have a minimal elevation, such as not to create a tipping hazard. For the purpose of this specification it must be expected that up to 8 EUS’s (with N = 4) end up on movable platforms.

5.3.11. All EUS’s must have lifting lugs that allow them to be relocated if NCNR laboratory circumstances dictate.

5.3.12. The weight and dimensions of EUSs must be minimized (subject to the design and review process that is laid out in the SOW and their different requirements as laid out in the “End User Station List” included at the end of this specification).

6. Plumbing

6.1. The plumbing for the indoors portion of the helium recovery system must be assembled from modular components (for example a modular system equivalent, or similar to, Tri‐Clamp Sanitary Tubing and fittings as well as all‐metal flexible spools, such as bellows, that may be custom manufactured). It is highly preferred that the entire indoor plumbing system, with the exception of the internals of the EUSs and

HMSs, be assembled from one and the same size and type tubing.

6.2. The plumbing for the outdoors portion (one single run between G100 and F100) of the helium recovery system must be one single welded structure, so that no gasket material is exposed to the elements. (See Attachment 2 – Beam overlay stations and

Plumbing Layout, Power Point drawing) (Reference 10.1)

6.3. Wherever possible, standardized (identical) lengths of plumbing spools must be used, so that these spools are interchangeable. The need for interchangeability must determine the tolerance on the length. Standard lengths with appropriate tolerance follow from the Government’s need to facilitate maintenance of the research facility

(i.e. take parts of the plumbing system apart and rebuild on a regular basis).

6.4. To improve maneuverability the standardized lengths of the plumbing spools must be in between 6 and 7 feet (including any Tri‐Clamp ferules, if so chosen).

6.5. Viton gaskets must be used for all plumbing connections that are not welded (note only a few welds are allowed, i.e. only one: the outdoors recovery tube run). The exception is in‐between the end user inputs and the heater input (see chapter on

EUSs), where Teflon gaskets must be used.

6.6. Besides providing modularity, this plumbing specification serves to minimize (if not essentially eliminate) onsite welding at the NCNR.

6.7. Plumbing design Basis: The NCNR has made a determination that if 2.5 inch Tri‐

Clamp Sanitary Tubing (or equivalent) is used for the entire helium recovery manifold, the pressure drop during a maximum flow condition of twice the rate specified in this specification (i.e. 2 x 150 = 300 LLHE per hour, see chapter 3) will not exceed 0.5 psi when the distance between the collection point and the helium bladder is assumed to be 500 ft (which is conservative). Hence it is specified to assemble the entire plumbing system out of 2.5 inch Tri‐Clamp Sanitary Tubing (or equivalent). This conservative estimate also serves the expandability of the system as specified above.

6.8. Mounting of the plumbing to existing structures in the NCNR Laboratories must be designed and executed such as to allow easy removal of the plumbing, so that the existing structures can be easily rearranged during occasional repurposing of the structures present in the NCNR Laboratories.

6.9. The C100 helium recovery branch manifold must contain one 2.5” Tri‐Clamp ball valve that is pneumatically operated. This valve must fail closed (“fail” is absence of air pressure) through application of a mechanical spring. Compressed Air for the valve operator is available in the vicinity of the valve location. The electrical connection for the solenoid valve that operates the valve operator will be provided by the Government. The function of this valve is to establish Reactor Building confinement in the event such is called for. This valve is located in C100 near the north confinement wall penetration towards the plumbing backbone in G100 and the helium compression and liquefaction building F100. It’s approximate location is depicted by the red arrow in Attachment 2 – Beam overlay stations and Plumbing Layout, Power Point drawing. (Reference 10.1).

7. PLC and Computer requirements

7.1. The system must operate fully automatically, from the point of helium gas collection to the point of liquid helium delivery to the daughter dewars, while minimizing waste of liquid helium.

7.2. The system must be capable of sending system status and updates to a central

Human Machine Interface (HMI) computer in accordance with operator settings.

7.3. The system must be capable of sending status updates and alerts to system operators via email and/or text messaging.

7.4. Helium Recovery System maintenance reminders must be posted on the main HMI computer.

7.5. The system must have the ability to be controlled remotely (from outside of the NIST

Campus). The system must function normally even if the HMI computer is turned off.

7.6. All the helium recovery and liquification equipment must be controlled via PLC.

7.6.1. As a minimum, it must receive sensor inputs from:

7.6.1.1. Status of the HMSs solenoid valves

7.6.1.2. HMSs helium flow readings

7.6.1.3. HMSs helium purity readings

7.6.1.4. Helium plant: standby/liquefaction mode with all the details of the liquefaction process

7.6.1.5. Helium level (amount) in the mother dewar

7.6.1.6. Helium level (amount) in the two daughter dewars

7.6.1.7. Automatic helium purificator: regeneration / working mode

7.6.1.8. Helium recovery compressor(s): standby / compression mode

7.6.1.9. Inlet pressure at the bladder(s)

7.6.1.10. Temperature of inlet chilled water, if any, for liquefaction equipment (compressors, etc.)

7.6.2. The contractor should develop full alarming system for all components failure at least for the following cases

7.6.2.1. Each command must be positively verified for success; failure must generate an alarm.

7.6.2.2. Each analog signal must be checked against the minimum and maximum allowable limits. Exceeding these limits should cause an alarm.

7.6.2.3. All PLC hardware must be monitored. Failure must generate an alarm.

7.6.2.4. Each device that has its own PLC must forward any alarms to the main PLC using a straightforward communication protocol.

7.6.2.5. The alarm hierarchy must be transparent and properly documented.

7.6.2.6. The alarm system should have two buzzers, one in F100 and a second near the filling station in G100. Near each buzzer an

“silence/acknowledge” button should be placed.

7.7. System HMI computers must have a Graphic User Interface (GUI) representing the

HCRPL layout within NCNR and showing all the measured parameters (i.e. gas flow and gas purity readings, Helium Monitor Stations’ solenoid valves status, helium liquification status, automatic helium gas purificators status, liquid helium level readings in the mother and daughter dewars, etc) at their layout physical locations

7.8. All sensor outputs must be sent to and be able to be accessed and displayed from the PLC for control, diagnostics, and troubleshooting purposes.

7.9. Proposed PLC monitor screen layouts must be agreed to by NIST

7.10. The contractor must be responsible to develop and deliver the Human Machine

Interface (HMI) computer, engineering system software, including soft configurations, historical trending for the complete control and monitoring of the system.

7.10.1. This software must allow NIST's operators to communicate with the PLC. The program must be password protected only on a programming level.

7.10.2. The HMI computer must be located in G100 near the two daughter dewers.

7.10.3. The HMI as a minimum must be able to access all the sensor output data from the PLC to be used on its own user interface screens

7.10.4. Provide trending of all analog system parameters vs. time (flow pressure, temperature, etc., together with accumulative helium flow over user selectable time range.

7.10.5. Trending screen must be able to display multiple sensor outputs, using a pull‐ down menu, to display comparative output curves for diagnostics.

7.10.6. Show the status of all equipment modes and dynamic processes using a sensible averaging time for each status variable.

7.10.7. HMI must include main HMI screen development of independent screens.

There must be at least 3 screens, Main (system with transmitter readings), Trending, and Usage.

7.10.8. The HMI must have the ability to operate using “remote desktop” from computers outside NIST.

7.10.9. The PLC must be able to send all alarms to a mobile phone via SMS (“text messages”)

7.10.10. The vendor must supply the development license and software manual for HMI and PLC in order to provide for NIST to make changes in the future.

7.10.11. The control system should provide ability to build different reports about system operation:

7.10.11.1. System operations report over a user defined time frame.

7.10.11.2. Report on how many and which dewars were filled during a user defined time frame.

7.11. The Contractor must work with NIST in developing the HMI screen interface. The final screen layouts must be approved by the Contracting Officer Representative

(COR).

7.12. Upon total loss or partial loss of electricity the PLC and HMI must be able to reboot themselves upon resumption of power. Upon resumption of power the PLC and

HMI must revert to the setting prior to power loss.

7.13. The liquification system must continue to operate as specified even if the HMI computer is power off.

7.14. The Contractor must provide documented source codes for all software and soft configurations developed by the Contractor for the project in a ready‐to‐compile electronic format along with licenses for software to open, edit and deploy files.

7.15. Number of significant digits for sensor readings must be agreed upon.

7.16. All the measurements must be logged in the HMI system.

7.17. Manufacturer of the HMI software must be the same as the PLC software.

7.18. Appropriate size HMI monitor screen to fit the system plan view must not be less than 19”

7.19. HMI touch screen not necessary, keyboard and mouse are preferred

7.20. All PLC and HMI equipment must be industrial grade able to operate 24/7 continuously.

7.21. Equipment must be protected against dust and debris.

7.22. For any PC employing an operating system: only the services used for control systems operation and maintenance must be enabled.

7.23. Wireless communication, wireless sensors and Remote Terminal Units (RTU’s) must not be used unless there is significant cost savings. Each case must be documented and justified, and must be approved by the COR

7.24. The Contractor must provide documentation detailing all applications, utilities, system services, scripts, configuration files, databases, and all other software required and the appropriate configurations, including revisions and/or patch levels for each of the computer systems associated with the control system. The

Contractor must provide a listing of services required for any computer system running control system applications or required to interface the control system applications. The listing must include all ports and services required for normal operation as well as any other ports and services required for emergency operation.

The listing must also include an explanation or cross reference to justify why each service is necessary for operation. The Contractor must verify and provide documentation that all services are patched to current status.

7.25. The Contractor must configure hosts with least privilege file and account access and provide documentation of the configuration. The Contractor must configure the necessary system services to execute at the least user privilege level possible for that service and provide documentation of the configuration. The Contractor must document that changing or disabling access to such files and functions has been completed.

7.26. The HMI software must be easily re‐installed by NIST personnel in the event of a Operation System upgrade that is pushed by NIST.

8. 250 liter Daughter Dewars specifications:

8.1. Cryofab CMSH series or similar

8.2. Non‐magnetic

8.3. Crane lifting points

8.4. Electrical Pressure Building Systems for liquid helium transfer and Digital

Superconducting Liquid Level System (with touch screen) both connected to main

PLC control

8.5. One port for automatic liquid helium transferring from mother to daughter dewar via VJ fill line coming from F100

8.6. Two ports for simultaneous liquid helium transferring from daughter to two transport dewar via 3/8” OD He transfer line

8.7. ½” MNPT Vent Valve

8.8. Compound Pressure Gauge 30" Hg‐0‐15 PSI

8.9. Emergency pressure relief valves

8.10. Locking Wheels

8.11. Pull Handles

8.12. Each daughter dewar must be equipped with one liquid helium transferring line, 3/8” OD, for transfer from 250 Lt daughter dewar to 100 liter transport dewars. Each transfer line must have a manual Shut Off Valve

8.13. Two(2) required

9. 100 liter Transport Dewars specifications:

9.1. Cryofab CMSH series or similar

9.2. Non‐magnetic

9.3. Crane lifting points

9.4. Superconducting Liquid Level System (level sensor, digital level reader safely attached to the dewar, all necessary cablings and connectors)

9.5. One port liquid helium transferring using 3/8” OD He transfer line

9.6. ½” MNPT Vent Valve

9.7. Compound Pressure Gauge 30" Hg‐0‐15 PSI

9.8. Emergency pressure relief valves

9.9. Wheels

9.10. Pull handles

9.11. Twenty (20) Required

10. References

10.1 Attachment 2 – Beam overlay stations and Plumbing Layout, Power Point drawing

11. Appendix

11.1. Helium Monitor Station (HMS) and End‐User Station (EUS) typical diagram

11.2. End‐user Stations List

EUI number Location # of ports N

Room C100

1 BT1 4

2 BT2 4

(d A ir /H e

P u ri ty m et e r ex h au st

(a th e B ra n ch m an if o ld b al l va lv e

(b Fl o w m et e r

(c ‐w ay s o le n o id v al ve n o rm al ly c lo se d P

LC

c o n tr o lle d

(h El ec tr ic H e at e r

#1

#2

#N

(k

M an u al b al l v al ve

FN

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3 BT4 4

4 BT5 4

5 BT7 4

6 BT9 (MACS) 4

7 outside BT7 4

8 Cold sourse tank location 12

9 BT3 (future end‐user station) 0

10 BT6 (future end‐user station) 0

Building G100

11 NG7 SANS 4

12 PHADES 4

13 NG7 Interferometer 4

14 future end‐user station 0

15 NG6 PHYS 4

16 SuperSPINS (future end‐user station) 0

17 SPINS 4

18 SE area in North end of G100, loc.#1 8

19 SE area in North end of G100, loc.#2 8

20 DCS 4

21 VSANS 4

22 HFBS 4

23 CANDOR 4

24 MAGIC (future end‐user station) 0

25 PBR 4

26 NG‐C aCORN (PML) 4

27 NG‐B 30m 4

28 nSoft (future end‐user station) 0

29 NSE 4

30 SE prep station 8

31 South wall (next to filling station) 24

34 South wall ‐ filling station 0

Room B128 High Bay

32 High Bay east wall, loc.#1 8

33 High Bay east wall, loc.#2 8

Toatal 156