.01 Steam Piping (In Building)

1. All steam piping shall be graded in the direction of flow, 1" in 40 ft.  At all low points in the steam piping system a drip station shall be installed. 
2. Provide offsets and bends wherever possible to allow for expansion and to control pipe movement.  Provide anchors and expansion joints as required.
3. Steam piping shall be black steel Schedule 40 ASTM A-53, Grade B.  Use all steel valves for steam piping.
4. Joints 2" and smaller, screwed; 2-1/2" and larger, welded or flanged.  All high pressure piping welded.
1. All steam pipe strainers and traps shall be removed and cleaned prior to acceptance by the University.
5. ALL CLEANING WORK IN THIS SECTION MUST BE WITNESSED BY THE DEPARTMENT OF GENERAL SERVICES (FOR DGS PROJECTS) AND UNIVERSITY INSPECTOR TO BE ACCEPTABLE.
6. Drip legs shall be a minimum 1/2 the size of the steam main 18" in length with blow down valve at the bottom.  Trap line connection shall be located in the center of the drip leg.
7. Refer to 23 07 00 for Insulation.    

.02 Steam Condensate Return Piping (In Building)

1. All steam condensate shall drain completely by gravity or be pumped.  Steam pressure shall not be used to lift condensate after a trap.
2. All gravity return condensate lines shall be pitched 1" in 30' in the direction of flow.
3. All condensate return lines in buildings shall be Schedule 80 black steel, ASTM A-53, Grade B.  Use all steel valves for condensate piping.
4. Joints 2" and smaller shall be screwed; 2-1/2" and larger shall be welded or flanged.
5. Design professional shall not mix condensate return lines of different pressures, temperatures, and/or flash steam qualities unless at an atmospheric receiver that is vented to a safe place.
6. Open pits are prohibited for collecting condensate.
7. Condensate receivers must be vented to safe place.

.03 Steam and Steam Condensate Specialties

1. Traps and strainers shall be installed with isolation valves, check valves, and telltale drain to facilitate cleaning, maintenance and to check proper operation of trap.
2. Provide all traps with a minimum condensate collection leg of 18".
3. For low-pressure drips, use float and thermostatic.
4. For high-pressure drips use thermodynamic traps.
5. For modulating service use float and thermostatic.
6. Pressure Reducing Valves
1. The Main Steam Pressure Control Stations shall consist of an air-operated diaphragm control valve and a remotely-adjustable external air-operated pressure control pilot.  Direct spring-operated valves and valves with steam pilots will not be accepted.  Air lines shall be provided under BAS.
2. The diaphragm control valve shall have a flanged cast bronze body having a 250 psi pressure rating.  It shall have hardened stainless steel trim with a stellited seat ring.  The valve shall be single seated, and suitable for dead end service with a 250 psi pressure drip.  It shall operate on a 0 to 22 psi air signal from the control pilot and be normally closed (air to open).
3. The air-operated pressure control pilot shall be of the differential type suitable for readjustment from a remotely-located air loading panel.
4. The pressure controller shall be capable of maintaining outlet pressure within plus or minus 1/2 psi when passing flow from zero to the maximum specified, regardless of gradual inlet pressure variations.
5. The Steam Pressure Controller shall consist of a diaphragm control valve, type DDL or GPK, and a control pilot, Type UDDV, and a remote panel loader, Type PPF, all as manufactured by the Leslie Company or equal by Spence or Sarce.  Remote panel loader shall have integral filters or be proceeded by strainers.
6. Consideration shall be given to two-stage reduction when required by pressure and two-stage parallel reduction when required by varying load conditions.
7. All pressure-reducing valves shall have an ASME/National Board stamped safety valve set at the low pressure side maximum pressure, with sufficient relieving capacity for a fully open PRV and its bypass line, along with a pressure gauge on the low pressure side of the PRV.  The safety valve shall be piped full size minimum to a safe point of discharge outside the building.
8. The safety relief vent for PRV's serving systems of different pressures shall be piped independently of each other to a safe point outside the building.
9. Refer to Detail [23 xx xx .xx].  Details are not yet available in WEB-based manual. 
7. Y-TYPE PIPELINE STRAINERS
1. General:  Locate strainers to protect components from steam or condensate-born debris.  Install in entering line ahead of the following equipment, and elsewhere as indicated, if integral strainer is not included in equipment.
1. Heat Transfer Equipment
2. Pressure reducing or regulating valves.
3. Steam traps.
4. Temperature control valves.

2. Product Requirements:  Provide strainers full line size of connecting piping, with ends matching piping system materials.  Select strainers for respective working pressure of piping system.  Provide type 304 stainless steel screens, with perforations ( or mesh for sizes under 2:) per schedule below.       

   SERVICE	PIPE SIZE	Coarse Straining (typically at central plant equipment)	Medium Straining (typically at terminal equipment, i.e. with temperatures or pressure control valves)
   Steam	1/4 to 2"	1/16" (0.057)	1/32" (0.033) (20 mesh)
   	2 1/2" and up	1/16" (0.057)	3/64" (0.045)

1. Threaded Ends, 2" and Smaller:  Carbon steel body screwed screen retainer with centered blowdown fitted with drain plug.
2. Flanged Ends, 2 1/2" and Larger:  Steel body, bolted screen retainer with blowdown fitted with hose end drain valve.
3. Acceptable Manufacturers:  Subject to compliance with requirements, provide Y-type strainers of one of the following:
1. Apollo; Conbraco
2. Armstrong International
3. Hoffman Specialty ITT; Fluid Handling Div.
4. Metraflex Co.
5. Spirax Sarco
6. Watts Regulator Co.
3. Installation: Install Y-type strainers full size of pipeline, in accordance with manufacturer's installation instructions.
1. IMPORTANT:  Y-type strainers in horizontal steam or gas lines shall be installed so that the pocket is in the horizontal plane.  This prevents water collecting in the pocket, in order to avoid risk of serious equipment damage and safety hazard from water hammer and related stresses and to prevent any water droplets being carried over, which can cause erosion and affect heat transfer processes.helping to prevent water droplets being carried over, which can cause erosion and affect heat transfer processes.
2. On liquid systems the pocket should point vertically downwards.  This ensures that the removed debris is not drawn back into the upstream pipework during low flow conditions.Although it is advisable to install strainers in horizontal lines, this i snot always possible, and they can be installed in vertical pipelines if the flow is downwards, in which case the debris is naturally directed into the pocket.  Installation is prohibited with upward flow, as the strainer would have to be installed with the opening of the pocket pointing downwards and the debris would fall back down the pipe.
3. Install pipe nipple and hose end drain valve in strainer blowdown connection, full size of connection, except for strainers 2" and smaller installed ahead of control valves feeding individual terminals.
4. Where indicated, provide drain line from shutoff valve to plumbing drain, full size of blowdown connection.
5. Be sure to remove any temporary fine mesh start up screens if used during initial cleaning and flushing of systems.

.04 Blowdown Piping (Boiler)

1. For high pressure boilers (over 15 psig steam), specify a heat recover unit on the blowdown system.  Flash steam could be utilitzed at the deaerator or other low pressure applications and hot water could be used to pre-heat the boiler make-up water.
1. Verify with the University, or with the local municipal authority, the permissible maximum temperature of waste water.
2. Piping:  Schedule 80, black steel, welded.
3. Pipe to funnel type floor drain or approved receptor.

.05 Condensate Pumps  

1. Condensate pumps shall be duplex, not to exceed 1,800 rpm, with alternator; both pumps to come on at high level.  Discuss discharge head with the University.  Install check valves to prevent circulation through inactive pump.  See Detail 15G-C for piping at meter and condensate return pumps.
   1. Discharge shall have a ball or plug valve with memory stop to provide pump discharge pressure adjustment.
2. Consideration shall be given to using Pressure Powered condensate pumps by Spirax/Sarco or approved equal, where economically justified.
3. Pumps shall use air for pumping where compressed air is available. If application allows, steam pressured pumps are the preferred method.
4. For critical service where condensate return is required at all times, consider redundant pressured pumps capable of operation using high or low pressure steam systems when one steam system is not in service. 
5. Minimum of 36” clearance required for equipment maintenance access.

.06 Guide Specifications:

1. Design Professional shall carefully review and edit the guideline specifications below, adapting them as needed to achieve application-specific, fully developed specifications for each project.
2. These shall be edited using the process described in the instructions contained at the beginning of the document.  Proposed modifications shall be reviewed with OPP staff.
3. Finalized version shall be included in the project contract documents.  Use of other specifications is not acceptable.