The Spirax Sarco SCA series are maintainable carbon steel inverted bucket steam traps with in-line connections. They are suitable for a wide range of pressures and incorporate an integral strainer. The product is available with material certification to EN 10204 3.1.B as standard (certification must be specified at the time of order).

Sizes and Pipe Connections

• ½", ¾" and 1" screwed BSP T Rp (ISO 7-1) or NPT.
• DN15, DN20 and DN25 socket weld ends (ANSI B16.11 Class 3000).
• Flanged PN40, ANSI 150 and ANSI 300.

Pressure/Temperature Limits (ISO 6552)

Maximum operating conditions depend on the orifice size. The SCA 30 product is verified safe for use under full vacuum conditions.

Body design conditions	ANSI/ASME 300 (PN50)
PMA - Maximum allowable pressure	51 bar g
TMA - Maximum allowable temperature	400 °C
Designed for a maximum cold hydraulic test pressure of:	78 bar g

INFO

A - B: Flanged ANSI 300, screwed and socket weld. A - C: Flanged BS 4504 PN40 (ISO 7005.1). A - D: Flanged ANSI 150.

Differential Pressure Limitations

Size	3 bar	5 bar	11 bar	15 bar	30 bar	40 bar
DN15 (1/2")	SCA3	SCA5	SCA11	SCA15	SCA30	SCA40
DN20 (3/4")	SCA3	SCA5	SCA11	SCA15	SCA30	SCA40
DN25 (1")	SCA3	SCA5	SCA11	SCA15	SCA30	SCA40

The SCA15, SCA30 and SCA40 are available as standard and the SCA3, SCA5 and SCA11 to special request.

TIP

The pressure limit on the flange specified should be greater than the pressure limit of the internal mechanism.

• ANSI 150 (14.1 bar g): Mechanisms 3, 5, 11 (15 limited to 14.1 bar g)
• ANSI 300 (41.6 bar g): All versions
• PN40 (36.1 bar g): Mechanisms 3, 5, 11, 15, 30 (40 limited to 36.1 bar g)

Materials

No	Part	Material	Standard
1	Body	Carbon steel	ASTM A105
2	Cover	Carbon steel	A216 WCB
3*	Cover bolts	Steel	ASTM A193 Gr. B7
4	Bucket	Stainless steel	AISI 304-2B
5*	Screen	Stainless steel	AISI 304
6	Strainer cap	Stainless steel	AISI 416
7	Inlet tube	Stainless steel	AISI 304
8	Cover gasket	Reinforced exfoliated graphite	-
9	Valve seat	Stainless steel	AISI 440C
10	Valve guide plate	Stainless steel	AISI 304-2B
11*	Valve guide plate screws	Stainless steel	BS 6105 CI A2-70
12	Hinge pin	Stainless steel	AISI 304
13	Valve lever	Stainless steel	AISI 304-2B
14*	Valve head	Stainless steel	AISI 420
15	Spring pin	Stainless steel	AISI 304
16	Washer	Stainless steel	AISI 304
17	Starlock washer	Stainless steel	AISI 301
18	'S' type gasket	Stainless steel	AISI 304

* Note: Items 3 and 11 are not illustrated.

Dimensions and Weights

Dimensions (approximate) in mm:

Size	Screwed / SW (A)	PN40 (A1)	ANSI 150 (A1)	ANSI 300 (A1)	B	Withdrawal C	Withdrawal D
DN15 (1/2")	90	150	150	150	167	100	110
DN20 (3/4")	90	150	150	150	167	100	110
DN25 (1")	165	160	160	160	167	100	110

Weights (approximate) in kg:

Size	Screwed / SW	PN40	ANSI 150	ANSI 300
DN15 (1/2")	3.0	4.7	4.6	5.0
DN20 (3/4")	3.0	5.3	5.0	5.8
DN25 (1")	3.5	6.0	5.7	6.5

Capacities

Capacities are in accordance with ISO 7842.

Installation and Maintenance

WARNING

The cover gasket contains a thin stainless steel support ring which may cause physical injury if it is not handled and disposed of carefully.

Installation: The trap must be installed with the body upright so that the bucket is rising and falling vertically. The inlet and outlet connections should be in a horizontal plane, with the trap installed below the drain point so that a water seal can be maintained around the open end of the bucket.

How to fit valve and seat assembly: Isolate the inverted bucket steam trap, remove the body by undoing the cover bolts. Remove the complete bucket assembly by undoing the two screws. Remove the valve seat. Screw in the new valve seat to the torque figures shown, using a little jointing paste on the threads and making sure that joint faces are clean. Fix the new bucket assembly in position by using new screws which are supplied, centralise the valve to the orifice and tighten screws to the torque figures shown. Using new gaskets, refit the body to the torque figures shown.

Spare Parts

Available Spares	Item Numbers
Internal set (state pressure range)	4, 8, 9, 10, 11 (2 off)*, 12, 13, 14, 15, 16 (2 off), 17
Strainer set	5, 18
Cover and strainer gasket (packet of three)	8, 18

* Note: Item 11 (valve guide plate screws) are not shown.

Recommended Tightening Torques

Item	Part	A/F (mm)	Thread	Torque (N m)
3*	Cover bolts	14	M10	40 - 45
6	Strainer cap	32	M28	170 - 190
9	Valve seat	17	M16	35 - 40
11*	Valve guide plate screws	Posidrive	M4 x 6	2.5 - 3.0